diff --git a/db/migrate/20121223110942_devise_create_users.rb b/db/migrate/20121223110942_devise_create_users.rb
index c566b064dd..3e33003758 100644
--- a/db/migrate/20121223110942_devise_create_users.rb
+++ b/db/migrate/20121223110942_devise_create_users.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class DeviseCreateUsers < ActiveRecord::Migration
+class DeviseCreateUsers < ActiveRecord::Migration[4.2]
   def up
     create_table(:users) do |t|
       ## Database authenticatable
diff --git a/db/migrate/20121223115038_create_conferences_table.rb b/db/migrate/20121223115038_create_conferences_table.rb
index 2f2e170e9a..daf45b4a09 100644
--- a/db/migrate/20121223115038_create_conferences_table.rb
+++ b/db/migrate/20121223115038_create_conferences_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateConferencesTable < ActiveRecord::Migration
+class CreateConferencesTable < ActiveRecord::Migration[4.2]
   def up
     create_table :conferences do |t|
       t.string :guid, null: false
diff --git a/db/migrate/20121223115106_create_people_table.rb b/db/migrate/20121223115106_create_people_table.rb
index 63160bb8c1..3245e6e470 100644
--- a/db/migrate/20121223115106_create_people_table.rb
+++ b/db/migrate/20121223115106_create_people_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreatePeopleTable < ActiveRecord::Migration
+class CreatePeopleTable < ActiveRecord::Migration[5.0]
   def up
     create_table :people do |t|
       t.string :guid, null: false
diff --git a/db/migrate/20121223115117_create_rooms_table.rb b/db/migrate/20121223115117_create_rooms_table.rb
index 57cf72e67f..a0a9546195 100644
--- a/db/migrate/20121223115117_create_rooms_table.rb
+++ b/db/migrate/20121223115117_create_rooms_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateRoomsTable < ActiveRecord::Migration
+class CreateRoomsTable < ActiveRecord::Migration[5.0]
   def up
     create_table :rooms do |t|
       t.string :guid, null: false
diff --git a/db/migrate/20121223115125_create_tracks_table.rb b/db/migrate/20121223115125_create_tracks_table.rb
index 021712c8ef..aad6a3abab 100644
--- a/db/migrate/20121223115125_create_tracks_table.rb
+++ b/db/migrate/20121223115125_create_tracks_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateTracksTable < ActiveRecord::Migration
+class CreateTracksTable < ActiveRecord::Migration[5.0]
   def up
     create_table :tracks do |t|
       t.string :guid, null: false
diff --git a/db/migrate/20121223115135_create_events_table.rb b/db/migrate/20121223115135_create_events_table.rb
index 3e6b51ddd9..196dac5b65 100644
--- a/db/migrate/20121223115135_create_events_table.rb
+++ b/db/migrate/20121223115135_create_events_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateEventsTable < ActiveRecord::Migration
+class CreateEventsTable < ActiveRecord::Migration[5.0]
   def up
     create_table :events do |t|
       t.string :guid, null: false
diff --git a/db/migrate/20121223120413_create_event_types.rb b/db/migrate/20121223120413_create_event_types.rb
index f34dfa775c..e40fa5087d 100644
--- a/db/migrate/20121223120413_create_event_types.rb
+++ b/db/migrate/20121223120413_create_event_types.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateEventTypes < ActiveRecord::Migration
+class CreateEventTypes < ActiveRecord::Migration[5.0]
   def up
     create_table :event_types do |t|
       t.references :conference
diff --git a/db/migrate/20121223122307_create_event_people_table.rb b/db/migrate/20121223122307_create_event_people_table.rb
index 3ac46fa285..35be08cf12 100644
--- a/db/migrate/20121223122307_create_event_people_table.rb
+++ b/db/migrate/20121223122307_create_event_people_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateEventPeopleTable < ActiveRecord::Migration
+class CreateEventPeopleTable < ActiveRecord::Migration[5.0]
   def self.up
     create_table :event_people do |t|
       t.references :proposal
diff --git a/db/migrate/20121223122842_create_venue_table.rb b/db/migrate/20121223122842_create_venue_table.rb
index f2a07e393d..b6765b97cf 100644
--- a/db/migrate/20121223122842_create_venue_table.rb
+++ b/db/migrate/20121223122842_create_venue_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateVenueTable < ActiveRecord::Migration
+class CreateVenueTable < ActiveRecord::Migration[5.0]
   def up
     create_table :venues do |t|
       t.string :guid
diff --git a/db/migrate/20121223135240_create_roles_table.rb b/db/migrate/20121223135240_create_roles_table.rb
index fc3b5119f2..283bb2f414 100644
--- a/db/migrate/20121223135240_create_roles_table.rb
+++ b/db/migrate/20121223135240_create_roles_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateRolesTable < ActiveRecord::Migration
+class CreateRolesTable < ActiveRecord::Migration[5.0]
   def self.up
     create_table :roles do |t|
       t.string :name
diff --git a/db/migrate/20121223135447_user_roles_table.rb b/db/migrate/20121223135447_user_roles_table.rb
index 70aec74c2e..e58b2361ed 100644
--- a/db/migrate/20121223135447_user_roles_table.rb
+++ b/db/migrate/20121223135447_user_roles_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class UserRolesTable < ActiveRecord::Migration
+class UserRolesTable < ActiveRecord::Migration[5.0]
   def self.up
     create_table :roles_users, id: false do |t|
       t.references :role, :user
diff --git a/db/migrate/20121224144728_create_cfp_table.rb b/db/migrate/20121224144728_create_cfp_table.rb
index 03ef90dc6e..f3cd27729f 100644
--- a/db/migrate/20121224144728_create_cfp_table.rb
+++ b/db/migrate/20121224144728_create_cfp_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateCfpTable < ActiveRecord::Migration
+class CreateCfpTable < ActiveRecord::Migration[5.0]
   def up
     create_table :call_for_papers do |t|
       t.date :start_date, null: false
diff --git a/db/migrate/20130103134212_create_registrations_table.rb b/db/migrate/20130103134212_create_registrations_table.rb
index dc9a0cf53d..f6688dfef6 100644
--- a/db/migrate/20130103134212_create_registrations_table.rb
+++ b/db/migrate/20130103134212_create_registrations_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateRegistrationsTable < ActiveRecord::Migration
+class CreateRegistrationsTable < ActiveRecord::Migration[5.0]
   def up
     create_table :registrations do |t|
       t.references :person
diff --git a/db/migrate/20130104142209_create_comments.rb b/db/migrate/20130104142209_create_comments.rb
index 3e49125a4b..d08a40077d 100644
--- a/db/migrate/20130104142209_create_comments.rb
+++ b/db/migrate/20130104142209_create_comments.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateComments < ActiveRecord::Migration
+class CreateComments < ActiveRecord::Migration[4.2]
   def self.up
     create_table :comments do |t|
       t.string :title, limit: 50, default: ''
diff --git a/db/migrate/20130104142839_acts_as_commentable_upgrade_migration.rb b/db/migrate/20130104142839_acts_as_commentable_upgrade_migration.rb
index ff53ee5cc0..82b5982aef 100644
--- a/db/migrate/20130104142839_acts_as_commentable_upgrade_migration.rb
+++ b/db/migrate/20130104142839_acts_as_commentable_upgrade_migration.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ActsAsCommentableUpgradeMigration < ActiveRecord::Migration
+class ActsAsCommentableUpgradeMigration < ActiveRecord::Migration[4.2]
   def self.up
     rename_column :comments, :comment, :body
     add_column :comments, :subject, :string
diff --git a/db/migrate/20130105115603_create_event_attachments_table.rb b/db/migrate/20130105115603_create_event_attachments_table.rb
index 9de9fd2d81..770a47f7d4 100644
--- a/db/migrate/20130105115603_create_event_attachments_table.rb
+++ b/db/migrate/20130105115603_create_event_attachments_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateEventAttachmentsTable < ActiveRecord::Migration
+class CreateEventAttachmentsTable < ActiveRecord::Migration[4.2]
   def up
     create_table :event_attachments do |t|
       t.references :event
diff --git a/db/migrate/20130107112833_add_registration_dates_to_conferences_table.rb b/db/migrate/20130107112833_add_registration_dates_to_conferences_table.rb
index 5aff90b2a1..ca8b98b5ab 100644
--- a/db/migrate/20130107112833_add_registration_dates_to_conferences_table.rb
+++ b/db/migrate/20130107112833_add_registration_dates_to_conferences_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddRegistrationDatesToConferencesTable < ActiveRecord::Migration
+class AddRegistrationDatesToConferencesTable < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :registration_start_date, :date
     add_column :conferences, :registration_end_date, :date
diff --git a/db/migrate/20130107113653_remove_cfp_and_reg_booleans_from_conferences.rb b/db/migrate/20130107113653_remove_cfp_and_reg_booleans_from_conferences.rb
index 78c126b286..db7af6fd11 100644
--- a/db/migrate/20130107113653_remove_cfp_and_reg_booleans_from_conferences.rb
+++ b/db/migrate/20130107113653_remove_cfp_and_reg_booleans_from_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveCfpAndRegBooleansFromConferences < ActiveRecord::Migration
+class RemoveCfpAndRegBooleansFromConferences < ActiveRecord::Migration[4.2]
   def up
     remove_column :conferences, :cfp_open
     remove_column :conferences, :registration_open
diff --git a/db/migrate/20130107114930_create_versions.rb b/db/migrate/20130107114930_create_versions.rb
index 19020e9012..dfdd3b9716 100644
--- a/db/migrate/20130107114930_create_versions.rb
+++ b/db/migrate/20130107114930_create_versions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateVersions < ActiveRecord::Migration
+class CreateVersions < ActiveRecord::Migration[4.2]
   def self.up
     create_table :versions do |t|
       t.string   :item_type, null: false
diff --git a/db/migrate/20130113105652_create_email_table.rb b/db/migrate/20130113105652_create_email_table.rb
index 8a38dfd4ba..d8da0a5114 100644
--- a/db/migrate/20130113105652_create_email_table.rb
+++ b/db/migrate/20130113105652_create_email_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateEmailTable < ActiveRecord::Migration
+class CreateEmailTable < ActiveRecord::Migration[4.2]
   def up
     create_table :email_settings do |t|
       t.references :conference
diff --git a/db/migrate/20130113132225_add_subjects_to_email_settings.rb b/db/migrate/20130113132225_add_subjects_to_email_settings.rb
index 8242c1fbc5..8183fa3fe0 100644
--- a/db/migrate/20130113132225_add_subjects_to_email_settings.rb
+++ b/db/migrate/20130113132225_add_subjects_to_email_settings.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddSubjectsToEmailSettings < ActiveRecord::Migration
+class AddSubjectsToEmailSettings < ActiveRecord::Migration[4.2]
   def change
     add_column :email_settings, :registration_subject, :string
     add_column :email_settings, :accepted_subject, :string
diff --git a/db/migrate/20130117130949_add_logo_to_conferences_table.rb b/db/migrate/20130117130949_add_logo_to_conferences_table.rb
index 47197b08c9..27a4741aa0 100644
--- a/db/migrate/20130117130949_add_logo_to_conferences_table.rb
+++ b/db/migrate/20130117130949_add_logo_to_conferences_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddLogoToConferencesTable < ActiveRecord::Migration
+class AddLogoToConferencesTable < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :logo_file_name, :string
     add_column :conferences, :logo_content_type, :string
diff --git a/db/migrate/20130120104029_change_arrival_registrations_date_to_datetime.rb b/db/migrate/20130120104029_change_arrival_registrations_date_to_datetime.rb
index 326b9a1215..43aa5b2619 100644
--- a/db/migrate/20130120104029_change_arrival_registrations_date_to_datetime.rb
+++ b/db/migrate/20130120104029_change_arrival_registrations_date_to_datetime.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangeArrivalRegistrationsDateToDatetime < ActiveRecord::Migration
+class ChangeArrivalRegistrationsDateToDatetime < ActiveRecord::Migration[4.2]
   def up
     change_column :registrations, :arrival, :datetime
     change_column :registrations, :departure, :datetime
diff --git a/db/migrate/20130131100257_add_minimum_and_maximum_abstract_lengths_to_event_types.rb b/db/migrate/20130131100257_add_minimum_and_maximum_abstract_lengths_to_event_types.rb
index 240e4ed801..2712c51c5a 100644
--- a/db/migrate/20130131100257_add_minimum_and_maximum_abstract_lengths_to_event_types.rb
+++ b/db/migrate/20130131100257_add_minimum_and_maximum_abstract_lengths_to_event_types.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddMinimumAndMaximumAbstractLengthsToEventTypes < ActiveRecord::Migration
+class AddMinimumAndMaximumAbstractLengthsToEventTypes < ActiveRecord::Migration[4.2]
   def change
     add_column :event_types, :minimum_abstract_length, :integer, default: 0
     add_column :event_types, :maximum_abstract_length, :integer, default: 500
diff --git a/db/migrate/20130202091022_add_dietary_choice_to_conferences.rb b/db/migrate/20130202091022_add_dietary_choice_to_conferences.rb
index b0e7a917df..8938307d59 100644
--- a/db/migrate/20130202091022_add_dietary_choice_to_conferences.rb
+++ b/db/migrate/20130202091022_add_dietary_choice_to_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDietaryChoiceToConferences < ActiveRecord::Migration
+class AddDietaryChoiceToConferences < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :use_dietary_choices, :boolean, default: false
   end
diff --git a/db/migrate/20130202091051_create_dietary_choices_table.rb b/db/migrate/20130202091051_create_dietary_choices_table.rb
index 1ab353d48d..a05d9c5858 100644
--- a/db/migrate/20130202091051_create_dietary_choices_table.rb
+++ b/db/migrate/20130202091051_create_dietary_choices_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateDietaryChoicesTable < ActiveRecord::Migration
+class CreateDietaryChoicesTable < ActiveRecord::Migration[4.2]
   def up
     create_table :dietary_choices do |t|
       t.references :conference
diff --git a/db/migrate/20130202091229_add_dietary_choice_to_registration.rb b/db/migrate/20130202091229_add_dietary_choice_to_registration.rb
index 343de790f3..62288f98f4 100644
--- a/db/migrate/20130202091229_add_dietary_choice_to_registration.rb
+++ b/db/migrate/20130202091229_add_dietary_choice_to_registration.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDietaryChoiceToRegistration < ActiveRecord::Migration
+class AddDietaryChoiceToRegistration < ActiveRecord::Migration[4.2]
   def change
     add_column :registrations, :dietary_choice_id, :integer
   end
diff --git a/db/migrate/20130202093137_add_dietary_text_to_registration.rb b/db/migrate/20130202093137_add_dietary_text_to_registration.rb
index 6a1e356d3d..f6777c9e06 100644
--- a/db/migrate/20130202093137_add_dietary_text_to_registration.rb
+++ b/db/migrate/20130202093137_add_dietary_text_to_registration.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDietaryTextToRegistration < ActiveRecord::Migration
+class AddDietaryTextToRegistration < ActiveRecord::Migration[4.2]
   def change
     add_column :registrations, :other_dietary_choice, :text
   end
diff --git a/db/migrate/20130202102024_add_handicapped_access_to_registrations.rb b/db/migrate/20130202102024_add_handicapped_access_to_registrations.rb
index ad5d85daef..a807dbd31d 100644
--- a/db/migrate/20130202102024_add_handicapped_access_to_registrations.rb
+++ b/db/migrate/20130202102024_add_handicapped_access_to_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddHandicappedAccessToRegistrations < ActiveRecord::Migration
+class AddHandicappedAccessToRegistrations < ActiveRecord::Migration[4.2]
   def change
     add_column :registrations, :handicapped_access_required, :boolean, default: false
   end
diff --git a/db/migrate/20130202130737_create_supporter_level_table.rb b/db/migrate/20130202130737_create_supporter_level_table.rb
index 60e1d08b25..fdd57f6082 100644
--- a/db/migrate/20130202130737_create_supporter_level_table.rb
+++ b/db/migrate/20130202130737_create_supporter_level_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateSupporterLevelTable < ActiveRecord::Migration
+class CreateSupporterLevelTable < ActiveRecord::Migration[4.2]
   def up
     create_table :supporter_levels do |t|
       t.references :conference
diff --git a/db/migrate/20130202130923_create_table_supporter_registrations.rb b/db/migrate/20130202130923_create_table_supporter_registrations.rb
index 00f03e6498..ecd13ead1f 100644
--- a/db/migrate/20130202130923_create_table_supporter_registrations.rb
+++ b/db/migrate/20130202130923_create_table_supporter_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateTableSupporterRegistrations < ActiveRecord::Migration
+class CreateTableSupporterRegistrations < ActiveRecord::Migration[4.2]
   def up
     create_table :supporter_registrations do |t|
       t.references :registration
diff --git a/db/migrate/20130202131932_add_use_supporter_levels_to_conferences.rb b/db/migrate/20130202131932_add_use_supporter_levels_to_conferences.rb
index 53247ccc02..3f67c93be4 100644
--- a/db/migrate/20130202131932_add_use_supporter_levels_to_conferences.rb
+++ b/db/migrate/20130202131932_add_use_supporter_levels_to_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddUseSupporterLevelsToConferences < ActiveRecord::Migration
+class AddUseSupporterLevelsToConferences < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :use_supporter_levels, :boolean, default: false
   end
diff --git a/db/migrate/20130206192339_rename_attending_social_events_with_partner.rb b/db/migrate/20130206192339_rename_attending_social_events_with_partner.rb
index cb0fb6d976..d2074a46b7 100644
--- a/db/migrate/20130206192339_rename_attending_social_events_with_partner.rb
+++ b/db/migrate/20130206192339_rename_attending_social_events_with_partner.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RenameAttendingSocialEventsWithPartner < ActiveRecord::Migration
+class RenameAttendingSocialEventsWithPartner < ActiveRecord::Migration[4.2]
   def up
     rename_column :registrations, :attending_social_events_with_partner, :attending_with_partner
   end
diff --git a/db/migrate/20130211170728_add_irc_nick_to_people_table.rb b/db/migrate/20130211170728_add_irc_nick_to_people_table.rb
index 060b85c1a2..d4edb34f75 100644
--- a/db/migrate/20130211170728_add_irc_nick_to_people_table.rb
+++ b/db/migrate/20130211170728_add_irc_nick_to_people_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIrcNickToPeopleTable < ActiveRecord::Migration
+class AddIrcNickToPeopleTable < ActiveRecord::Migration[4.2]
   def change
     add_column :people, :irc_nickname, :string
   end
diff --git a/db/migrate/20130216070725_create_social_events_table.rb b/db/migrate/20130216070725_create_social_events_table.rb
index 22f89dbcbe..be2da46eff 100644
--- a/db/migrate/20130216070725_create_social_events_table.rb
+++ b/db/migrate/20130216070725_create_social_events_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateSocialEventsTable < ActiveRecord::Migration
+class CreateSocialEventsTable < ActiveRecord::Migration[4.2]
   def up
     create_table :social_events do |t|
       t.references :conference
diff --git a/db/migrate/20130216120112_create_registrations_social_events_table.rb b/db/migrate/20130216120112_create_registrations_social_events_table.rb
index a6a98d1638..b12e8f12be 100644
--- a/db/migrate/20130216120112_create_registrations_social_events_table.rb
+++ b/db/migrate/20130216120112_create_registrations_social_events_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateRegistrationsSocialEventsTable < ActiveRecord::Migration
+class CreateRegistrationsSocialEventsTable < ActiveRecord::Migration[4.2]
   def up
     create_table :registrations_social_events, id: false do |t|
       t.references :registration, :social_event
diff --git a/db/migrate/20130216122155_set_registration_defaults_to_false.rb b/db/migrate/20130216122155_set_registration_defaults_to_false.rb
index 3a2069a545..00eb403f83 100644
--- a/db/migrate/20130216122155_set_registration_defaults_to_false.rb
+++ b/db/migrate/20130216122155_set_registration_defaults_to_false.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class SetRegistrationDefaultsToFalse < ActiveRecord::Migration
+class SetRegistrationDefaultsToFalse < ActiveRecord::Migration[4.2]
   def up
     change_column :registrations, :using_affiliated_lodging, :boolean, default: false
   end
diff --git a/db/migrate/20130216122417_add_special_needs_field_to_registrations.rb b/db/migrate/20130216122417_add_special_needs_field_to_registrations.rb
index 9339819c25..4a3561f3fa 100644
--- a/db/migrate/20130216122417_add_special_needs_field_to_registrations.rb
+++ b/db/migrate/20130216122417_add_special_needs_field_to_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddSpecialNeedsFieldToRegistrations < ActiveRecord::Migration
+class AddSpecialNeedsFieldToRegistrations < ActiveRecord::Migration[4.2]
   def change
     add_column :registrations, :other_special_needs, :text
   end
diff --git a/db/migrate/20130515125823_change_attachment_default.rb b/db/migrate/20130515125823_change_attachment_default.rb
index 4f73cf4d79..26fac0555b 100644
--- a/db/migrate/20130515125823_change_attachment_default.rb
+++ b/db/migrate/20130515125823_change_attachment_default.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangeAttachmentDefault < ActiveRecord::Migration
+class ChangeAttachmentDefault < ActiveRecord::Migration[4.2]
   def up
     change_column_default(:event_attachments, :public, true)
   end
diff --git a/db/migrate/20130515131420_change_venue_types.rb b/db/migrate/20130515131420_change_venue_types.rb
index 00b1cb0ae9..bca82803d1 100644
--- a/db/migrate/20130515131420_change_venue_types.rb
+++ b/db/migrate/20130515131420_change_venue_types.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangeVenueTypes < ActiveRecord::Migration
+class ChangeVenueTypes < ActiveRecord::Migration[4.2]
   def up
     change_column :venues, :name, :text
     change_column :venues, :address, :text
diff --git a/db/migrate/20130626095459_add_video_id_to_events.rb b/db/migrate/20130626095459_add_video_id_to_events.rb
index da79497f88..3f5c6213ae 100644
--- a/db/migrate/20130626095459_add_video_id_to_events.rb
+++ b/db/migrate/20130626095459_add_video_id_to_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddVideoIdToEvents < ActiveRecord::Migration
+class AddVideoIdToEvents < ActiveRecord::Migration[4.2]
   def change
     add_column :events, :video_id, :string
     add_column :events, :video_type, :string
diff --git a/db/migrate/20130705055128_add_revision_to_conference.rb b/db/migrate/20130705055128_add_revision_to_conference.rb
index d8e3070ca0..620ed4bcba 100644
--- a/db/migrate/20130705055128_add_revision_to_conference.rb
+++ b/db/migrate/20130705055128_add_revision_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddRevisionToConference < ActiveRecord::Migration
+class AddRevisionToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :revision, :integer
   end
diff --git a/db/migrate/20130711043459_create_events_registrations_table.rb b/db/migrate/20130711043459_create_events_registrations_table.rb
index 9275880a36..32270a966e 100644
--- a/db/migrate/20130711043459_create_events_registrations_table.rb
+++ b/db/migrate/20130711043459_create_events_registrations_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateEventsRegistrationsTable < ActiveRecord::Migration
+class CreateEventsRegistrationsTable < ActiveRecord::Migration[4.2]
   def up
     create_table :events_registrations, id: false do |t|
       t.references :registration, :event
diff --git a/db/migrate/20130711044247_add_require_registration_to_events.rb b/db/migrate/20130711044247_add_require_registration_to_events.rb
index a4f2f64375..5e4fe4e98b 100644
--- a/db/migrate/20130711044247_add_require_registration_to_events.rb
+++ b/db/migrate/20130711044247_add_require_registration_to_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddRequireRegistrationToEvents < ActiveRecord::Migration
+class AddRequireRegistrationToEvents < ActiveRecord::Migration[4.2]
   def change
     add_column :events, :require_registration, :boolean
   end
diff --git a/db/migrate/20130712072609_add_attended_to_registrations.rb b/db/migrate/20130712072609_add_attended_to_registrations.rb
index 598f432e71..3cccc62fcc 100644
--- a/db/migrate/20130712072609_add_attended_to_registrations.rb
+++ b/db/migrate/20130712072609_add_attended_to_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddAttendedToRegistrations < ActiveRecord::Migration
+class AddAttendedToRegistrations < ActiveRecord::Migration[4.2]
   def change
     add_column :registrations, :attended, :boolean, default: 0
   end
diff --git a/db/migrate/20130728055450_add_schedule_changes_to_call_for_papers.rb b/db/migrate/20130728055450_add_schedule_changes_to_call_for_papers.rb
index 4078efc059..a042384ddb 100644
--- a/db/migrate/20130728055450_add_schedule_changes_to_call_for_papers.rb
+++ b/db/migrate/20130728055450_add_schedule_changes_to_call_for_papers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddScheduleChangesToCallForPapers < ActiveRecord::Migration
+class AddScheduleChangesToCallForPapers < ActiveRecord::Migration[4.2]
   def change
     add_column :call_for_papers, :schedule_changes, :boolean, default: 0
   end
diff --git a/db/migrate/20130815085420_create_votes.rb b/db/migrate/20130815085420_create_votes.rb
index d0e514a686..ff64cb2b60 100644
--- a/db/migrate/20130815085420_create_votes.rb
+++ b/db/migrate/20130815085420_create_votes.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateVotes < ActiveRecord::Migration
+class CreateVotes < ActiveRecord::Migration[4.2]
   def up
     create_table :votes do |t|
       t.references :person
diff --git a/db/migrate/20130815201317_add_rating_to_call_for_papers.rb b/db/migrate/20130815201317_add_rating_to_call_for_papers.rb
index b5537596b9..2a0e69f779 100644
--- a/db/migrate/20130815201317_add_rating_to_call_for_papers.rb
+++ b/db/migrate/20130815201317_add_rating_to_call_for_papers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddRatingToCallForPapers < ActiveRecord::Migration
+class AddRatingToCallForPapers < ActiveRecord::Migration[4.2]
   def change
     add_column :call_for_papers, :rating, :integer, null: 1
   end
diff --git a/db/migrate/20130815201511_add_rating_desc_to_call_for_papers.rb b/db/migrate/20130815201511_add_rating_desc_to_call_for_papers.rb
index 67c8f020b1..d995ab7bc5 100644
--- a/db/migrate/20130815201511_add_rating_desc_to_call_for_papers.rb
+++ b/db/migrate/20130815201511_add_rating_desc_to_call_for_papers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddRatingDescToCallForPapers < ActiveRecord::Migration
+class AddRatingDescToCallForPapers < ActiveRecord::Migration[4.2]
   def change
     add_column :call_for_papers, :rating_desc, :text
   end
diff --git a/db/migrate/20130821094246_add_volunteer_to_registrations.rb b/db/migrate/20130821094246_add_volunteer_to_registrations.rb
index b0719aab7f..82956f59eb 100644
--- a/db/migrate/20130821094246_add_volunteer_to_registrations.rb
+++ b/db/migrate/20130821094246_add_volunteer_to_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddVolunteerToRegistrations < ActiveRecord::Migration
+class AddVolunteerToRegistrations < ActiveRecord::Migration[4.2]
   def change
     add_column :registrations, :volunteer, :boolean
   end
diff --git a/db/migrate/20130821102003_add_volunteer_experience_to_registrations.rb b/db/migrate/20130821102003_add_volunteer_experience_to_registrations.rb
index 6621e54758..259007585f 100644
--- a/db/migrate/20130821102003_add_volunteer_experience_to_registrations.rb
+++ b/db/migrate/20130821102003_add_volunteer_experience_to_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddVolunteerExperienceToRegistrations < ActiveRecord::Migration
+class AddVolunteerExperienceToRegistrations < ActiveRecord::Migration[4.2]
   def change
     add_column :people, :volunteer_experience, :text
   end
diff --git a/db/migrate/20130821102047_add_tshirt_to_people.rb b/db/migrate/20130821102047_add_tshirt_to_people.rb
index b25b702325..042645e0d6 100644
--- a/db/migrate/20130821102047_add_tshirt_to_people.rb
+++ b/db/migrate/20130821102047_add_tshirt_to_people.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddTshirtToPeople < ActiveRecord::Migration
+class AddTshirtToPeople < ActiveRecord::Migration[4.2]
   def change
     add_column :people, :tshirt, :string
   end
diff --git a/db/migrate/20130821102108_add_mobile_to_people.rb b/db/migrate/20130821102108_add_mobile_to_people.rb
index 550b63aad0..e855da6fd4 100644
--- a/db/migrate/20130821102108_add_mobile_to_people.rb
+++ b/db/migrate/20130821102108_add_mobile_to_people.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddMobileToPeople < ActiveRecord::Migration
+class AddMobileToPeople < ActiveRecord::Migration[4.2]
   def change
     add_column :people, :mobile, :string
   end
diff --git a/db/migrate/20130821102404_add_languages_to_people.rb b/db/migrate/20130821102404_add_languages_to_people.rb
index 3d55498824..ed61cff03d 100644
--- a/db/migrate/20130821102404_add_languages_to_people.rb
+++ b/db/migrate/20130821102404_add_languages_to_people.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddLanguagesToPeople < ActiveRecord::Migration
+class AddLanguagesToPeople < ActiveRecord::Migration[4.2]
   def change
     add_column :people, :languages, :string
   end
diff --git a/db/migrate/20130821102543_add_use_vpositions_to_conferences.rb b/db/migrate/20130821102543_add_use_vpositions_to_conferences.rb
index 2505449529..b6be17adf0 100644
--- a/db/migrate/20130821102543_add_use_vpositions_to_conferences.rb
+++ b/db/migrate/20130821102543_add_use_vpositions_to_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddUseVpositionsToConferences < ActiveRecord::Migration
+class AddUseVpositionsToConferences < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :use_vpositions, :boolean
   end
diff --git a/db/migrate/20130821102618_add_use_vdays_to_conferences.rb b/db/migrate/20130821102618_add_use_vdays_to_conferences.rb
index ce92131696..3949ed9a9a 100644
--- a/db/migrate/20130821102618_add_use_vdays_to_conferences.rb
+++ b/db/migrate/20130821102618_add_use_vdays_to_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddUseVdaysToConferences < ActiveRecord::Migration
+class AddUseVdaysToConferences < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :use_vdays, :boolean
   end
diff --git a/db/migrate/20130821133651_create_vpositions.rb b/db/migrate/20130821133651_create_vpositions.rb
index dd9d3ed471..5383497ba5 100644
--- a/db/migrate/20130821133651_create_vpositions.rb
+++ b/db/migrate/20130821133651_create_vpositions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateVpositions < ActiveRecord::Migration
+class CreateVpositions < ActiveRecord::Migration[4.2]
   def up
     create_table :vpositions do |t|
       t.references :conference
diff --git a/db/migrate/20130821133850_create_vdays.rb b/db/migrate/20130821133850_create_vdays.rb
index 9c05c279a2..090058f058 100644
--- a/db/migrate/20130821133850_create_vdays.rb
+++ b/db/migrate/20130821133850_create_vdays.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateVdays < ActiveRecord::Migration
+class CreateVdays < ActiveRecord::Migration[4.2]
   def up
     create_table :vdays do |t|
       t.references :conference
diff --git a/db/migrate/20131022131450_add_created_at_to_supporter_registrations.rb b/db/migrate/20131022131450_add_created_at_to_supporter_registrations.rb
index bdeede4d35..9891c329b4 100644
--- a/db/migrate/20131022131450_add_created_at_to_supporter_registrations.rb
+++ b/db/migrate/20131022131450_add_created_at_to_supporter_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddCreatedAtToSupporterRegistrations < ActiveRecord::Migration
+class AddCreatedAtToSupporterRegistrations < ActiveRecord::Migration[4.2]
   def change
     add_column :supporter_registrations, :created_at, :datetime
   end
diff --git a/db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb b/db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb
index 89b9fa80a6..e9933ea76d 100644
--- a/db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb
+++ b/db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangeDefaultRatingInCallForPapers < ActiveRecord::Migration
+class ChangeDefaultRatingInCallForPapers < ActiveRecord::Migration[4.2]
   def up
     change_column :call_for_papers, :rating, :integer, default: 3
   end
diff --git a/db/migrate/20131228214532_create_vchoices.rb b/db/migrate/20131228214532_create_vchoices.rb
index 0114f53203..1bc4b4aae3 100644
--- a/db/migrate/20131228214532_create_vchoices.rb
+++ b/db/migrate/20131228214532_create_vchoices.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateVchoices < ActiveRecord::Migration
+class CreateVchoices < ActiveRecord::Migration[4.2]
   def change
     create_table :vchoices do |t|
       t.references :vday
diff --git a/db/migrate/20131229072532_registrations_vchoices.rb b/db/migrate/20131229072532_registrations_vchoices.rb
index 3110ea2ea9..050cc423e8 100644
--- a/db/migrate/20131229072532_registrations_vchoices.rb
+++ b/db/migrate/20131229072532_registrations_vchoices.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RegistrationsVchoices < ActiveRecord::Migration
+class RegistrationsVchoices < ActiveRecord::Migration[4.2]
   def up
     create_table :registrations_vchoices, id: false do |t|
       t.references :registration, :vchoice
diff --git a/db/migrate/20140109190643_create_questions.rb b/db/migrate/20140109190643_create_questions.rb
index e78b4d20ca..f6ebef0907 100644
--- a/db/migrate/20140109190643_create_questions.rb
+++ b/db/migrate/20140109190643_create_questions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateQuestions < ActiveRecord::Migration
+class CreateQuestions < ActiveRecord::Migration[4.2]
   def change
     create_table :questions do |t|
       t.string :title
diff --git a/db/migrate/20140109190844_create_question_types.rb b/db/migrate/20140109190844_create_question_types.rb
index 7a8f07d3af..f5d98e7e0b 100644
--- a/db/migrate/20140109190844_create_question_types.rb
+++ b/db/migrate/20140109190844_create_question_types.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateQuestionTypes < ActiveRecord::Migration
+class CreateQuestionTypes < ActiveRecord::Migration[4.2]
   def change
     create_table :question_types do |t|
       t.string :title
diff --git a/db/migrate/20140109191042_create_answers.rb b/db/migrate/20140109191042_create_answers.rb
index 5356bda7dc..e93e8cc511 100644
--- a/db/migrate/20140109191042_create_answers.rb
+++ b/db/migrate/20140109191042_create_answers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateAnswers < ActiveRecord::Migration
+class CreateAnswers < ActiveRecord::Migration[4.2]
   def change
     create_table :answers do |t|
       t.string :title
diff --git a/db/migrate/20140109191145_create_qanswers.rb b/db/migrate/20140109191145_create_qanswers.rb
index 4bc395887e..fa8f9a5d2a 100644
--- a/db/migrate/20140109191145_create_qanswers.rb
+++ b/db/migrate/20140109191145_create_qanswers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateQanswers < ActiveRecord::Migration
+class CreateQanswers < ActiveRecord::Migration[4.2]
   def change
     create_table :qanswers do |t|
       t.references :question
diff --git a/db/migrate/20140109191321_create_conferences_questions.rb b/db/migrate/20140109191321_create_conferences_questions.rb
index 659de9a44f..60b4c2de30 100644
--- a/db/migrate/20140109191321_create_conferences_questions.rb
+++ b/db/migrate/20140109191321_create_conferences_questions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateConferencesQuestions < ActiveRecord::Migration
+class CreateConferencesQuestions < ActiveRecord::Migration[4.2]
   def change
     create_table :conferences_questions, id: false do |t|
       t.references :conference
diff --git a/db/migrate/20140112192801_create_qanswers_registrations.rb b/db/migrate/20140112192801_create_qanswers_registrations.rb
index 9501defe7d..28ad596bb4 100644
--- a/db/migrate/20140112192801_create_qanswers_registrations.rb
+++ b/db/migrate/20140112192801_create_qanswers_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateQanswersRegistrations < ActiveRecord::Migration
+class CreateQanswersRegistrations < ActiveRecord::Migration[4.2]
   def change
     create_table :qanswers_registrations, id: false do |t|
       t.references :registration, null: false
diff --git a/db/migrate/20140212172244_create_difficulty_levels.rb b/db/migrate/20140212172244_create_difficulty_levels.rb
index 02faced054..cb762f736f 100644
--- a/db/migrate/20140212172244_create_difficulty_levels.rb
+++ b/db/migrate/20140212172244_create_difficulty_levels.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateDifficultyLevels < ActiveRecord::Migration
+class CreateDifficultyLevels < ActiveRecord::Migration[4.2]
   def change
     create_table :difficulty_levels do |t|
       t.references :conference
diff --git a/db/migrate/20140212175251_add_use_difficulty_levels_to_conference.rb b/db/migrate/20140212175251_add_use_difficulty_levels_to_conference.rb
index 02391e2a8a..17c2000822 100644
--- a/db/migrate/20140212175251_add_use_difficulty_levels_to_conference.rb
+++ b/db/migrate/20140212175251_add_use_difficulty_levels_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddUseDifficultyLevelsToConference < ActiveRecord::Migration
+class AddUseDifficultyLevelsToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :use_difficulty_levels, :boolean, default: false
   end
diff --git a/db/migrate/20140213122424_add_difficulty_level_id_to_events.rb b/db/migrate/20140213122424_add_difficulty_level_id_to_events.rb
index e4594d1e6f..ea91a3d012 100644
--- a/db/migrate/20140213122424_add_difficulty_level_id_to_events.rb
+++ b/db/migrate/20140213122424_add_difficulty_level_id_to_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDifficultyLevelIdToEvents < ActiveRecord::Migration
+class AddDifficultyLevelIdToEvents < ActiveRecord::Migration[4.2]
   def change
     add_column :events, :difficulty_level_id, :integer
   end
diff --git a/db/migrate/20140304192527_add_use_volunteers_to_conference.rb b/db/migrate/20140304192527_add_use_volunteers_to_conference.rb
index d7c030fa70..a19fd10c0c 100644
--- a/db/migrate/20140304192527_add_use_volunteers_to_conference.rb
+++ b/db/migrate/20140304192527_add_use_volunteers_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddUseVolunteersToConference < ActiveRecord::Migration
+class AddUseVolunteersToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :use_volunteers, :boolean
   end
diff --git a/db/migrate/20140305102505_use_vdays_vpositions_defaults.rb b/db/migrate/20140305102505_use_vdays_vpositions_defaults.rb
index 052ea3150f..4e1df6edc6 100644
--- a/db/migrate/20140305102505_use_vdays_vpositions_defaults.rb
+++ b/db/migrate/20140305102505_use_vdays_vpositions_defaults.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class UseVdaysVpositionsDefaults < ActiveRecord::Migration
+class UseVdaysVpositionsDefaults < ActiveRecord::Migration[4.2]
   def up
     change_column :conferences, :use_vpositions, :boolean, default: false
     change_column :conferences, :use_vdays, :boolean, default: false
diff --git a/db/migrate/20140319143547_rename_video_to_media_on_events.rb b/db/migrate/20140319143547_rename_video_to_media_on_events.rb
index f5d6d771b6..b864c49130 100644
--- a/db/migrate/20140319143547_rename_video_to_media_on_events.rb
+++ b/db/migrate/20140319143547_rename_video_to_media_on_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RenameVideoToMediaOnEvents < ActiveRecord::Migration
+class RenameVideoToMediaOnEvents < ActiveRecord::Migration[4.2]
   def up
     rename_column :events, :video_id, :media_id
     rename_column :events, :video_type, :media_type
diff --git a/db/migrate/20140401094729_add_schedule_public_to_call_for_papers.rb b/db/migrate/20140401094729_add_schedule_public_to_call_for_papers.rb
index fb82814f0e..858596866e 100644
--- a/db/migrate/20140401094729_add_schedule_public_to_call_for_papers.rb
+++ b/db/migrate/20140401094729_add_schedule_public_to_call_for_papers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddSchedulePublicToCallForPapers < ActiveRecord::Migration
+class AddSchedulePublicToCallForPapers < ActiveRecord::Migration[4.2]
   def change
     add_column :call_for_papers, :schedule_public, :boolean
   end
diff --git a/db/migrate/20140414131028_add_video_to_conferences.rb b/db/migrate/20140414131028_add_video_to_conferences.rb
index ea7811099e..debc1d5862 100644
--- a/db/migrate/20140414131028_add_video_to_conferences.rb
+++ b/db/migrate/20140414131028_add_video_to_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddVideoToConferences < ActiveRecord::Migration
+class AddVideoToConferences < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :media_id, :string
     add_column :conferences, :media_type, :string
diff --git a/db/migrate/20140514140013_remove_rating_desc_from_cfp.rb b/db/migrate/20140514140013_remove_rating_desc_from_cfp.rb
index 8f25368d86..dde12496ec 100644
--- a/db/migrate/20140514140013_remove_rating_desc_from_cfp.rb
+++ b/db/migrate/20140514140013_remove_rating_desc_from_cfp.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveRatingDescFromCfp < ActiveRecord::Migration
+class RemoveRatingDescFromCfp < ActiveRecord::Migration[4.2]
   def up
     remove_column :call_for_papers, :rating_desc
   end
diff --git a/db/migrate/20140528072939_add_color_to_conference.rb b/db/migrate/20140528072939_add_color_to_conference.rb
index 37aa6f990e..e06615a596 100644
--- a/db/migrate/20140528072939_add_color_to_conference.rb
+++ b/db/migrate/20140528072939_add_color_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddColorToConference < ActiveRecord::Migration
+class AddColorToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :color, :string, default: '#000000'
   end
diff --git a/db/migrate/20140528084706_add_description_to_conference.rb b/db/migrate/20140528084706_add_description_to_conference.rb
index 9e1612fce4..9d6a2e1bf7 100644
--- a/db/migrate/20140528084706_add_description_to_conference.rb
+++ b/db/migrate/20140528084706_add_description_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDescriptionToConference < ActiveRecord::Migration
+class AddDescriptionToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :description, :text
   end
diff --git a/db/migrate/20140528115842_add_registration_description_to_conference.rb b/db/migrate/20140528115842_add_registration_description_to_conference.rb
index 3886549adc..9d58fd9b2a 100644
--- a/db/migrate/20140528115842_add_registration_description_to_conference.rb
+++ b/db/migrate/20140528115842_add_registration_description_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddRegistrationDescriptionToConference < ActiveRecord::Migration
+class AddRegistrationDescriptionToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :registration_description, :text
   end
diff --git a/db/migrate/20140529133052_add_ticket_description_to_conference.rb b/db/migrate/20140529133052_add_ticket_description_to_conference.rb
index bbd4b9979f..d1789ad576 100644
--- a/db/migrate/20140529133052_add_ticket_description_to_conference.rb
+++ b/db/migrate/20140529133052_add_ticket_description_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddTicketDescriptionToConference < ActiveRecord::Migration
+class AddTicketDescriptionToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :ticket_description, :text
   end
diff --git a/db/migrate/20140529133228_add_description_to_supporter_level.rb b/db/migrate/20140529133228_add_description_to_supporter_level.rb
index 68b0480682..b736fad399 100644
--- a/db/migrate/20140529133228_add_description_to_supporter_level.rb
+++ b/db/migrate/20140529133228_add_description_to_supporter_level.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDescriptionToSupporterLevel < ActiveRecord::Migration
+class AddDescriptionToSupporterLevel < ActiveRecord::Migration[4.2]
   def change
     add_column :supporter_levels, :description, :text
   end
diff --git a/db/migrate/20140529133339_add_ticket_price_to_supporter_level.rb b/db/migrate/20140529133339_add_ticket_price_to_supporter_level.rb
index cc993529ea..bc8259d424 100644
--- a/db/migrate/20140529133339_add_ticket_price_to_supporter_level.rb
+++ b/db/migrate/20140529133339_add_ticket_price_to_supporter_level.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddTicketPriceToSupporterLevel < ActiveRecord::Migration
+class AddTicketPriceToSupporterLevel < ActiveRecord::Migration[4.2]
   def change
     add_column :supporter_levels, :ticket_price, :string
   end
diff --git a/db/migrate/20140530082708_remove_color_defaults.rb b/db/migrate/20140530082708_remove_color_defaults.rb
index d5b7fe50ac..355d8db3b3 100644
--- a/db/migrate/20140530082708_remove_color_defaults.rb
+++ b/db/migrate/20140530082708_remove_color_defaults.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveColorDefaults < ActiveRecord::Migration
+class RemoveColorDefaults < ActiveRecord::Migration[4.2]
   def change
     change_column_default(:tracks, :color, nil)
     change_column_default(:conferences, :color, nil)
diff --git a/db/migrate/20140603092041_create_openids.rb b/db/migrate/20140603092041_create_openids.rb
index 93cf271d54..c09167dfc2 100644
--- a/db/migrate/20140603092041_create_openids.rb
+++ b/db/migrate/20140603092041_create_openids.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateOpenids < ActiveRecord::Migration
+class CreateOpenids < ActiveRecord::Migration[4.2]
   def change
     create_table :openids do |t|
       t.string :provider
diff --git a/db/migrate/20140604061951_create_lodgings.rb b/db/migrate/20140604061951_create_lodgings.rb
index e9192e332f..749541c519 100644
--- a/db/migrate/20140604061951_create_lodgings.rb
+++ b/db/migrate/20140604061951_create_lodgings.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateLodgings < ActiveRecord::Migration
+class CreateLodgings < ActiveRecord::Migration[4.2]
   def change
     create_table :lodgings do |t|
       t.string :name
diff --git a/db/migrate/20140604142949_remove_hard_deadline_from_call_for_papers.rb b/db/migrate/20140604142949_remove_hard_deadline_from_call_for_papers.rb
index b1e3d05251..7baf1f26e8 100644
--- a/db/migrate/20140604142949_remove_hard_deadline_from_call_for_papers.rb
+++ b/db/migrate/20140604142949_remove_hard_deadline_from_call_for_papers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveHardDeadlineFromCallForPapers < ActiveRecord::Migration
+class RemoveHardDeadlineFromCallForPapers < ActiveRecord::Migration[4.2]
   def up
     remove_column :call_for_papers, :hard_deadline
   end
diff --git a/db/migrate/20140605055802_create_sponsorship_levels.rb b/db/migrate/20140605055802_create_sponsorship_levels.rb
index e192b2c13f..6a56b0f548 100644
--- a/db/migrate/20140605055802_create_sponsorship_levels.rb
+++ b/db/migrate/20140605055802_create_sponsorship_levels.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateSponsorshipLevels < ActiveRecord::Migration
+class CreateSponsorshipLevels < ActiveRecord::Migration[4.2]
   def change
     create_table :sponsorship_levels do |t|
       t.string :title
diff --git a/db/migrate/20140605115251_create_sponsors.rb b/db/migrate/20140605115251_create_sponsors.rb
index fb2751d22d..9a10508acb 100644
--- a/db/migrate/20140605115251_create_sponsors.rb
+++ b/db/migrate/20140605115251_create_sponsors.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateSponsors < ActiveRecord::Migration
+class CreateSponsors < ActiveRecord::Migration[4.2]
   def change
     create_table :sponsors do |t|
       t.string :name
diff --git a/db/migrate/20140605125153_update_event_states.rb b/db/migrate/20140605125153_update_event_states.rb
index e5302c8e08..d8f189b5e4 100644
--- a/db/migrate/20140605125153_update_event_states.rb
+++ b/db/migrate/20140605125153_update_event_states.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class UpdateEventStates < ActiveRecord::Migration
+class UpdateEventStates < ActiveRecord::Migration[4.2]
   def change
     execute "UPDATE events SET state='new' WHERE state = 'review';"
   end
diff --git a/db/migrate/20140606102331_add_sponsor_description_to_conference.rb b/db/migrate/20140606102331_add_sponsor_description_to_conference.rb
index eb01d770bb..b0825a0cce 100644
--- a/db/migrate/20140606102331_add_sponsor_description_to_conference.rb
+++ b/db/migrate/20140606102331_add_sponsor_description_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddSponsorDescriptionToConference < ActiveRecord::Migration
+class AddSponsorDescriptionToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :sponsor_description, :text
   end
diff --git a/db/migrate/20140606102358_add_sponsor_email_to_conference.rb b/db/migrate/20140606102358_add_sponsor_email_to_conference.rb
index 7446746b8c..07b2d73e1c 100644
--- a/db/migrate/20140606102358_add_sponsor_email_to_conference.rb
+++ b/db/migrate/20140606102358_add_sponsor_email_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddSponsorEmailToConference < ActiveRecord::Migration
+class AddSponsorEmailToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :sponsor_email, :string
   end
diff --git a/db/migrate/20140609172219_add_person_attributes_to_user.rb b/db/migrate/20140609172219_add_person_attributes_to_user.rb
index e9b1fceea0..44c8a320f0 100644
--- a/db/migrate/20140609172219_add_person_attributes_to_user.rb
+++ b/db/migrate/20140609172219_add_person_attributes_to_user.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddPersonAttributesToUser < ActiveRecord::Migration
+class AddPersonAttributesToUser < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :name, :string
     add_column :users, :email_public, :boolean
diff --git a/db/migrate/20140610064046_create_photos.rb b/db/migrate/20140610064046_create_photos.rb
index 5e1aab05bf..594ed5666d 100644
--- a/db/migrate/20140610064046_create_photos.rb
+++ b/db/migrate/20140610064046_create_photos.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreatePhotos < ActiveRecord::Migration
+class CreatePhotos < ActiveRecord::Migration[4.2]
   def change
     create_table :photos do |t|
       t.text :description
diff --git a/db/migrate/20140610163947_create_event_users.rb b/db/migrate/20140610163947_create_event_users.rb
index 6165fd2c52..cb1afd7410 100644
--- a/db/migrate/20140610163947_create_event_users.rb
+++ b/db/migrate/20140610163947_create_event_users.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateEventUsers < ActiveRecord::Migration
+class CreateEventUsers < ActiveRecord::Migration[4.2]
   class TempPerson < ActiveRecord::Base
     self.table_name = 'people'
   end
diff --git a/db/migrate/20140610165551_migrate_data_person_to_user.rb b/db/migrate/20140610165551_migrate_data_person_to_user.rb
index cbdb046c14..ff8f401cfb 100644
--- a/db/migrate/20140610165551_migrate_data_person_to_user.rb
+++ b/db/migrate/20140610165551_migrate_data_person_to_user.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MigrateDataPersonToUser < ActiveRecord::Migration
+class MigrateDataPersonToUser < ActiveRecord::Migration[4.2]
   class TempPerson < ActiveRecord::Base
     self.table_name = 'people'
   end
diff --git a/db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb b/db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb
index b6858f7eed..a4332c8efc 100644
--- a/db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb
+++ b/db/migrate/20140610173021_change_person_id_to_user_id_in_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangePersonIdToUserIdInRegistrations < ActiveRecord::Migration
+class ChangePersonIdToUserIdInRegistrations < ActiveRecord::Migration[4.2]
   class TempPerson < ActiveRecord::Base
     self.table_name = 'people'
   end
diff --git a/db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb b/db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb
index 38f397008a..707dae48d9 100644
--- a/db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb
+++ b/db/migrate/20140611123926_change_person_id_to_user_id_in_votes.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangePersonIdToUserIdInVotes < ActiveRecord::Migration
+class ChangePersonIdToUserIdInVotes < ActiveRecord::Migration[4.2]
   class TempPerson < ActiveRecord::Base
     self.table_name = 'people'
   end
diff --git a/db/migrate/20140612141123_add_color_to_event_type.rb b/db/migrate/20140612141123_add_color_to_event_type.rb
index ffe250a492..c06ae070ff 100644
--- a/db/migrate/20140612141123_add_color_to_event_type.rb
+++ b/db/migrate/20140612141123_add_color_to_event_type.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddColorToEventType < ActiveRecord::Migration
+class AddColorToEventType < ActiveRecord::Migration[4.2]
   def change
     add_column :event_types, :color, :string
   end
diff --git a/db/migrate/20140612181230_add_social_urls_to_conference.rb b/db/migrate/20140612181230_add_social_urls_to_conference.rb
index 44cd337371..ea8e70dd0d 100644
--- a/db/migrate/20140612181230_add_social_urls_to_conference.rb
+++ b/db/migrate/20140612181230_add_social_urls_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddSocialUrlsToConference < ActiveRecord::Migration
+class AddSocialUrlsToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :twitter_url, :string
     add_column :conferences, :facebook_url, :string
diff --git a/db/migrate/20140613083115_add_photo_to_venue.rb b/db/migrate/20140613083115_add_photo_to_venue.rb
index 8d2f7a5253..4fc4d99160 100644
--- a/db/migrate/20140613083115_add_photo_to_venue.rb
+++ b/db/migrate/20140613083115_add_photo_to_venue.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddPhotoToVenue < ActiveRecord::Migration
+class AddPhotoToVenue < ActiveRecord::Migration[4.2]
   def change
     add_column :venues, :photo_file_name, :string
     add_column :venues, :photo_content_type, :string
diff --git a/db/migrate/20140614171853_add_lodging_description_to_conference.rb b/db/migrate/20140614171853_add_lodging_description_to_conference.rb
index 7e34573aa8..7d5812af38 100644
--- a/db/migrate/20140614171853_add_lodging_description_to_conference.rb
+++ b/db/migrate/20140614171853_add_lodging_description_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddLodgingDescriptionToConference < ActiveRecord::Migration
+class AddLodgingDescriptionToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :lodging_description, :text
   end
diff --git a/db/migrate/20140614174354_add_website_link_to_lodging.rb b/db/migrate/20140614174354_add_website_link_to_lodging.rb
index d7f6d80981..1f869046bd 100644
--- a/db/migrate/20140614174354_add_website_link_to_lodging.rb
+++ b/db/migrate/20140614174354_add_website_link_to_lodging.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddWebsiteLinkToLodging < ActiveRecord::Migration
+class AddWebsiteLinkToLodging < ActiveRecord::Migration[4.2]
   def change
     add_column :lodgings, :website_link, :string
   end
diff --git a/db/migrate/20140616131731_add_make_conference_public_to_conference.rb b/db/migrate/20140616131731_add_make_conference_public_to_conference.rb
index 20c41a521d..ef4f88c011 100644
--- a/db/migrate/20140616131731_add_make_conference_public_to_conference.rb
+++ b/db/migrate/20140616131731_add_make_conference_public_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddMakeConferencePublicToConference < ActiveRecord::Migration
+class AddMakeConferencePublicToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :make_conference_public, :boolean, default: false
   end
diff --git a/db/migrate/20140616132153_create_targets.rb b/db/migrate/20140616132153_create_targets.rb
index 3f5e4b7e7b..0c32cbd843 100644
--- a/db/migrate/20140616132153_create_targets.rb
+++ b/db/migrate/20140616132153_create_targets.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateTargets < ActiveRecord::Migration
+class CreateTargets < ActiveRecord::Migration[4.2]
   def change
     create_table :targets do |t|
       t.integer :conference_id
diff --git a/db/migrate/20140616132456_create_campaigns.rb b/db/migrate/20140616132456_create_campaigns.rb
index edb06d5850..fd1b878d95 100644
--- a/db/migrate/20140616132456_create_campaigns.rb
+++ b/db/migrate/20140616132456_create_campaigns.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateCampaigns < ActiveRecord::Migration
+class CreateCampaigns < ActiveRecord::Migration[4.2]
   def change
     create_table :campaigns do |t|
       t.integer :conference_id
diff --git a/db/migrate/20140617140018_add_checkboxes_for_splash_components_to_conference.rb b/db/migrate/20140617140018_add_checkboxes_for_splash_components_to_conference.rb
index a716507cb3..63dbb554a0 100644
--- a/db/migrate/20140617140018_add_checkboxes_for_splash_components_to_conference.rb
+++ b/db/migrate/20140617140018_add_checkboxes_for_splash_components_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddCheckboxesForSplashComponentsToConference < ActiveRecord::Migration
+class AddCheckboxesForSplashComponentsToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :include_registrations_in_splash, :boolean, default: false
     add_column :conferences, :include_sponsors_in_splash, :boolean, default: false
diff --git a/db/migrate/20140617141918_add_include_cfp_in_splash_to_call_for_papers.rb b/db/migrate/20140617141918_add_include_cfp_in_splash_to_call_for_papers.rb
index e8ab8e2311..07ec088617 100644
--- a/db/migrate/20140617141918_add_include_cfp_in_splash_to_call_for_papers.rb
+++ b/db/migrate/20140617141918_add_include_cfp_in_splash_to_call_for_papers.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIncludeCfpInSplashToCallForPapers < ActiveRecord::Migration
+class AddIncludeCfpInSplashToCallForPapers < ActiveRecord::Migration[4.2]
   def change
     add_column :call_for_papers, :include_cfp_in_splash, :boolean, default: false
   end
diff --git a/db/migrate/20140617145048_add_venue_checkboxes_to_venue.rb b/db/migrate/20140617145048_add_venue_checkboxes_to_venue.rb
index fc6d82d308..50eeab787c 100644
--- a/db/migrate/20140617145048_add_venue_checkboxes_to_venue.rb
+++ b/db/migrate/20140617145048_add_venue_checkboxes_to_venue.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddVenueCheckboxesToVenue < ActiveRecord::Migration
+class AddVenueCheckboxesToVenue < ActiveRecord::Migration[4.2]
   def change
     add_column :venues, :include_venue_in_splash, :boolean, default: false
     add_column :venues, :include_lodgings_in_splash, :boolean, default: false
diff --git a/db/migrate/20140620130306_add_banner_photo_to_conference.rb b/db/migrate/20140620130306_add_banner_photo_to_conference.rb
index c6ca6ecc15..95d3377c3b 100644
--- a/db/migrate/20140620130306_add_banner_photo_to_conference.rb
+++ b/db/migrate/20140620130306_add_banner_photo_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddBannerPhotoToConference < ActiveRecord::Migration
+class AddBannerPhotoToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :banner_photo_file_name, :string
     add_column :conferences, :banner_photo_content_type, :string
diff --git a/db/migrate/20140620134535_add_include_banner_in_splash_to_conference.rb b/db/migrate/20140620134535_add_include_banner_in_splash_to_conference.rb
index 229172ea11..5b4dcbc85c 100644
--- a/db/migrate/20140620134535_add_include_banner_in_splash_to_conference.rb
+++ b/db/migrate/20140620134535_add_include_banner_in_splash_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIncludeBannerInSplashToConference < ActiveRecord::Migration
+class AddIncludeBannerInSplashToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :include_banner_in_splash, :boolean, default: false
   end
diff --git a/db/migrate/20140623100942_create_visits.rb b/db/migrate/20140623100942_create_visits.rb
index 49d409b641..a5e4394b46 100644
--- a/db/migrate/20140623100942_create_visits.rb
+++ b/db/migrate/20140623100942_create_visits.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateVisits < ActiveRecord::Migration
+class CreateVisits < ActiveRecord::Migration[4.2]
   def change
     create_table :visits do |t|
       t.uuid :visitor_id
diff --git a/db/migrate/20140623101032_create_ahoy_events.rb b/db/migrate/20140623101032_create_ahoy_events.rb
index 63db8ba7ed..46440ed181 100644
--- a/db/migrate/20140623101032_create_ahoy_events.rb
+++ b/db/migrate/20140623101032_create_ahoy_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateAhoyEvents < ActiveRecord::Migration
+class CreateAhoyEvents < ActiveRecord::Migration[4.2]
   def change
     create_table :ahoy_events  do |t|
       t.uuid :visit_id
diff --git a/db/migrate/20140623150541_drop_person_and_event_person_tables.rb b/db/migrate/20140623150541_drop_person_and_event_person_tables.rb
index 779f445009..47eeb5f4e6 100644
--- a/db/migrate/20140623150541_drop_person_and_event_person_tables.rb
+++ b/db/migrate/20140623150541_drop_person_and_event_person_tables.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class DropPersonAndEventPersonTables < ActiveRecord::Migration
+class DropPersonAndEventPersonTables < ActiveRecord::Migration[4.2]
   def change
     drop_table :people
     drop_table :event_people
diff --git a/db/migrate/20140625112608_add_week_to_event.rb b/db/migrate/20140625112608_add_week_to_event.rb
index 810e5ceeae..9ea1f7c8c1 100644
--- a/db/migrate/20140625112608_add_week_to_event.rb
+++ b/db/migrate/20140625112608_add_week_to_event.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddWeekToEvent < ActiveRecord::Migration
+class AddWeekToEvent < ActiveRecord::Migration[4.2]
   class Event < ActiveRecord::Base
   end
 
diff --git a/db/migrate/20140625114813_add_week_to_registration.rb b/db/migrate/20140625114813_add_week_to_registration.rb
index fb6e966c8a..b3f6872b9d 100644
--- a/db/migrate/20140625114813_add_week_to_registration.rb
+++ b/db/migrate/20140625114813_add_week_to_registration.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddWeekToRegistration < ActiveRecord::Migration
+class AddWeekToRegistration < ActiveRecord::Migration[4.2]
   class Registration < ActiveRecord::Base
   end
 
diff --git a/db/migrate/20140627165718_add_instagram_url_to_conference.rb b/db/migrate/20140627165718_add_instagram_url_to_conference.rb
index bb6859d9ca..9181155c8e 100644
--- a/db/migrate/20140627165718_add_instagram_url_to_conference.rb
+++ b/db/migrate/20140627165718_add_instagram_url_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddInstagramUrlToConference < ActiveRecord::Migration
+class AddInstagramUrlToConference < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :instagram_url, :string
   end
diff --git a/db/migrate/20140701123203_add_events_per_week_to_conference.rb b/db/migrate/20140701123203_add_events_per_week_to_conference.rb
index ff2e082003..2c94ff1124 100644
--- a/db/migrate/20140701123203_add_events_per_week_to_conference.rb
+++ b/db/migrate/20140701123203_add_events_per_week_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddEventsPerWeekToConference < ActiveRecord::Migration
+class AddEventsPerWeekToConference < ActiveRecord::Migration[4.2]
   class TempVersion < ActiveRecord::Base
     self.table_name = 'versions'
     serialize :object_changes, HashWithIndifferentAccess
diff --git a/db/migrate/20140707120158_add_conference_dates_updates_to_email_settings.rb b/db/migrate/20140707120158_add_conference_dates_updates_to_email_settings.rb
index 6755eb3643..681c098a05 100644
--- a/db/migrate/20140707120158_add_conference_dates_updates_to_email_settings.rb
+++ b/db/migrate/20140707120158_add_conference_dates_updates_to_email_settings.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddConferenceDatesUpdatesToEmailSettings < ActiveRecord::Migration
+class AddConferenceDatesUpdatesToEmailSettings < ActiveRecord::Migration[4.2]
   def change
     add_column :email_settings, :send_on_updated_conference_dates, :boolean, default: true
     add_column :email_settings, :updated_conference_dates_subject, :string
diff --git a/db/migrate/20140710130608_add_conference_registration_dates_updates_to_email_settings.rb b/db/migrate/20140710130608_add_conference_registration_dates_updates_to_email_settings.rb
index 6c33a5a33b..df61c5ce1c 100644
--- a/db/migrate/20140710130608_add_conference_registration_dates_updates_to_email_settings.rb
+++ b/db/migrate/20140710130608_add_conference_registration_dates_updates_to_email_settings.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddConferenceRegistrationDatesUpdatesToEmailSettings < ActiveRecord::Migration
+class AddConferenceRegistrationDatesUpdatesToEmailSettings < ActiveRecord::Migration[4.2]
   def change
     add_column :email_settings, :send_on_updated_conference_registration_dates, :boolean, default: true
     add_column :email_settings, :updated_conference_registration_dates_subject, :string
diff --git a/db/migrate/20140711072651_add_description_and_resource_to_roles.rb b/db/migrate/20140711072651_add_description_and_resource_to_roles.rb
index ba803aecc1..a44d1f34b7 100644
--- a/db/migrate/20140711072651_add_description_and_resource_to_roles.rb
+++ b/db/migrate/20140711072651_add_description_and_resource_to_roles.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDescriptionAndResourceToRoles < ActiveRecord::Migration
+class AddDescriptionAndResourceToRoles < ActiveRecord::Migration[4.2]
   def change
     add_column :roles, :description, :string
     add_reference :roles, :resource, polymorphic: true
diff --git a/db/migrate/20140711113037_add_venue_update_to_email_settings.rb b/db/migrate/20140711113037_add_venue_update_to_email_settings.rb
index a03d170413..784c871816 100644
--- a/db/migrate/20140711113037_add_venue_update_to_email_settings.rb
+++ b/db/migrate/20140711113037_add_venue_update_to_email_settings.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddVenueUpdateToEmailSettings < ActiveRecord::Migration
+class AddVenueUpdateToEmailSettings < ActiveRecord::Migration[4.2]
   def change
     add_column :email_settings, :send_on_venue_update, :boolean, default: true
     add_column :email_settings, :venue_update_subject, :string
diff --git a/db/migrate/20140714141156_add_volunteer_fields_to_user.rb b/db/migrate/20140714141156_add_volunteer_fields_to_user.rb
index 293b179d2e..4c2299e40b 100644
--- a/db/migrate/20140714141156_add_volunteer_fields_to_user.rb
+++ b/db/migrate/20140714141156_add_volunteer_fields_to_user.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddVolunteerFieldsToUser < ActiveRecord::Migration
+class AddVolunteerFieldsToUser < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :mobile, :string
     add_column :users, :tshirt, :string
diff --git a/db/migrate/20140716115448_add_default_value_to_email_settings.rb b/db/migrate/20140716115448_add_default_value_to_email_settings.rb
index 404219fa53..6501c4d0a1 100644
--- a/db/migrate/20140716115448_add_default_value_to_email_settings.rb
+++ b/db/migrate/20140716115448_add_default_value_to_email_settings.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDefaultValueToEmailSettings < ActiveRecord::Migration
+class AddDefaultValueToEmailSettings < ActiveRecord::Migration[4.2]
   def up
     change_column :email_settings, :send_on_registration, :boolean, default: false
     change_column :email_settings, :send_on_accepted, :boolean, default: false
diff --git a/db/migrate/20140718103856_add_is_admin_to_users.rb b/db/migrate/20140718103856_add_is_admin_to_users.rb
index de5240581b..d057548f68 100644
--- a/db/migrate/20140718103856_add_is_admin_to_users.rb
+++ b/db/migrate/20140718103856_add_is_admin_to_users.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIsAdminToUsers < ActiveRecord::Migration
+class AddIsAdminToUsers < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :is_admin, :boolean, default: false
   end
diff --git a/db/migrate/20140719160903_create_delayed_jobs.rb b/db/migrate/20140719160903_create_delayed_jobs.rb
index d3ddfa0095..53ad78aebd 100644
--- a/db/migrate/20140719160903_create_delayed_jobs.rb
+++ b/db/migrate/20140719160903_create_delayed_jobs.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateDelayedJobs < ActiveRecord::Migration
+class CreateDelayedJobs < ActiveRecord::Migration[4.2]
   def self.up
     create_table :delayed_jobs, force: true do |table|
       table.integer  :priority, default: 0, null: false # Allows some jobs to jump to the front of the queue
diff --git a/db/migrate/20140724113107_add_call_for_papers_updates_to_email_settings.rb b/db/migrate/20140724113107_add_call_for_papers_updates_to_email_settings.rb
index dc4206b3c0..185cf00caf 100644
--- a/db/migrate/20140724113107_add_call_for_papers_updates_to_email_settings.rb
+++ b/db/migrate/20140724113107_add_call_for_papers_updates_to_email_settings.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddCallForPapersUpdatesToEmailSettings < ActiveRecord::Migration
+class AddCallForPapersUpdatesToEmailSettings < ActiveRecord::Migration[4.2]
   def change
     add_column :email_settings, :send_on_call_for_papers_dates_updates, :boolean, default: false
     add_column :email_settings, :send_on_call_for_papers_schedule_public, :boolean, default: false
diff --git a/db/migrate/20140724153520_create_subscriptions.rb b/db/migrate/20140724153520_create_subscriptions.rb
index 80a246df79..de772a7cc7 100644
--- a/db/migrate/20140724153520_create_subscriptions.rb
+++ b/db/migrate/20140724153520_create_subscriptions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateSubscriptions < ActiveRecord::Migration
+class CreateSubscriptions < ActiveRecord::Migration[4.2]
   def change
     create_table :subscriptions do |t|
       t.belongs_to :user
diff --git a/db/migrate/20140730104658_migrate_roles_for_cancancan.rb b/db/migrate/20140730104658_migrate_roles_for_cancancan.rb
index ed76b7c026..f72b419fbb 100644
--- a/db/migrate/20140730104658_migrate_roles_for_cancancan.rb
+++ b/db/migrate/20140730104658_migrate_roles_for_cancancan.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MigrateRolesForCancancan < ActiveRecord::Migration
+class MigrateRolesForCancancan < ActiveRecord::Migration[4.2]
   def up
     # Store the number of existing roles
     old_roles = Role.count
diff --git a/db/migrate/20140731153332_create_contacts.rb b/db/migrate/20140731153332_create_contacts.rb
index db76cd0904..7c37b4ff73 100644
--- a/db/migrate/20140731153332_create_contacts.rb
+++ b/db/migrate/20140731153332_create_contacts.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateContacts < ActiveRecord::Migration
+class CreateContacts < ActiveRecord::Migration[4.2]
   def change
     create_table :contacts do |t|
       t.string :social_tag
diff --git a/db/migrate/20140731165107_move_conference_contact_details_to_contact.rb b/db/migrate/20140731165107_move_conference_contact_details_to_contact.rb
index 2996da3811..4cf497370a 100644
--- a/db/migrate/20140731165107_move_conference_contact_details_to_contact.rb
+++ b/db/migrate/20140731165107_move_conference_contact_details_to_contact.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MoveConferenceContactDetailsToContact < ActiveRecord::Migration
+class MoveConferenceContactDetailsToContact < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20140801103645_create_commercials.rb b/db/migrate/20140801103645_create_commercials.rb
index bc73fb820e..0a288a68af 100644
--- a/db/migrate/20140801103645_create_commercials.rb
+++ b/db/migrate/20140801103645_create_commercials.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateCommercials < ActiveRecord::Migration
+class CreateCommercials < ActiveRecord::Migration[4.2]
   def change
     create_table :commercials do |t|
       t.string :commercial_id
diff --git a/db/migrate/20140801164901_move_conference_media_to_commercial.rb b/db/migrate/20140801164901_move_conference_media_to_commercial.rb
index 46cd17a568..5e6eb6a35d 100644
--- a/db/migrate/20140801164901_move_conference_media_to_commercial.rb
+++ b/db/migrate/20140801164901_move_conference_media_to_commercial.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MoveConferenceMediaToCommercial < ActiveRecord::Migration
+class MoveConferenceMediaToCommercial < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20140801170430_move_event_media_to_commercial.rb b/db/migrate/20140801170430_move_event_media_to_commercial.rb
index bc5f4488e0..c9196f1843 100644
--- a/db/migrate/20140801170430_move_event_media_to_commercial.rb
+++ b/db/migrate/20140801170430_move_event_media_to_commercial.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MoveEventMediaToCommercial < ActiveRecord::Migration
+class MoveEventMediaToCommercial < ActiveRecord::Migration[4.2]
   class TempEvent < ActiveRecord::Base
     self.table_name = 'events'
   end
diff --git a/db/migrate/20140804185823_create_registration_periods.rb b/db/migrate/20140804185823_create_registration_periods.rb
index e8814623f0..0684b84054 100644
--- a/db/migrate/20140804185823_create_registration_periods.rb
+++ b/db/migrate/20140804185823_create_registration_periods.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateRegistrationPeriods < ActiveRecord::Migration
+class CreateRegistrationPeriods < ActiveRecord::Migration[4.2]
   def up
     create_table :registration_periods do |t|
       t.integer :conference_id
diff --git a/db/migrate/20140812065531_move_conference_registration_data_to_registration_periods.rb b/db/migrate/20140812065531_move_conference_registration_data_to_registration_periods.rb
index 59e79b699b..e9eb3ed892 100644
--- a/db/migrate/20140812065531_move_conference_registration_data_to_registration_periods.rb
+++ b/db/migrate/20140812065531_move_conference_registration_data_to_registration_periods.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MoveConferenceRegistrationDataToRegistrationPeriods < ActiveRecord::Migration
+class MoveConferenceRegistrationDataToRegistrationPeriods < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20140819124315_rename_supporter_level_to_ticket.rb b/db/migrate/20140819124315_rename_supporter_level_to_ticket.rb
index c88ccba59a..017bb59e0a 100644
--- a/db/migrate/20140819124315_rename_supporter_level_to_ticket.rb
+++ b/db/migrate/20140819124315_rename_supporter_level_to_ticket.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RenameSupporterLevelToTicket < ActiveRecord::Migration
+class RenameSupporterLevelToTicket < ActiveRecord::Migration[4.2]
   def up
     rename_table :supporter_levels, :tickets
   end
diff --git a/db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb b/db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb
index 5c4b4de8e8..8a631bf696 100644
--- a/db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb
+++ b/db/migrate/20140820093735_migrating_supporter_registrations_to_ticket_users.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MigratingSupporterRegistrationsToTicketUsers < ActiveRecord::Migration
+class MigratingSupporterRegistrationsToTicketUsers < ActiveRecord::Migration[4.2]
   class TempSupporterRegistrations < ActiveRecord::Base
     self.table_name = 'supporter_registrations'
   end
diff --git a/db/migrate/20140820123503_assign_users_to_events.rb b/db/migrate/20140820123503_assign_users_to_events.rb
index a18f6da6cd..15ea8b1121 100644
--- a/db/migrate/20140820123503_assign_users_to_events.rb
+++ b/db/migrate/20140820123503_assign_users_to_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AssignUsersToEvents < ActiveRecord::Migration
+class AssignUsersToEvents < ActiveRecord::Migration[4.2]
   class TempEvent < ActiveRecord::Base
     self.table_name = 'events'
   end
diff --git a/db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb b/db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb
index db2d1bb8b3..24b40f9c7f 100644
--- a/db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb
+++ b/db/migrate/20140820124117_undo_wrong_migration20140801080705_add_users_to_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class UndoWrongMigration20140801080705AddUsersToEvents < ActiveRecord::Migration
+class UndoWrongMigration20140801080705AddUsersToEvents < ActiveRecord::Migration[7.0]
   class TempEvent < ActiveRecord::Base
     self.table_name = 'events'
   end
@@ -20,7 +20,7 @@ class Version < ActiveRecord::Base
   end
 
   def up
-    if ActiveRecord::Migrator.get_all_versions.include? 20140801080705
+    if ApplicationRecord.connection.migration_context.get_all_versions.include? 20140801080705
       user_deleted = TempUser.find_by(email: 'deleted@localhost.osem')
 
       TempEvent.all.each do |event|
diff --git a/db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb b/db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb
index 99e8714bab..913ba484e5 100644
--- a/db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb
+++ b/db/migrate/20140821103643_split_ticket_price_in_price_and_currency.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class SplitTicketPriceInPriceAndCurrency < ActiveRecord::Migration
+class SplitTicketPriceInPriceAndCurrency < ActiveRecord::Migration[4.2]
   class TempTicket < ActiveRecord::Base
     self.table_name = 'tickets'
   end
diff --git a/db/migrate/20140825091222_create_splashpages.rb b/db/migrate/20140825091222_create_splashpages.rb
index 4056d86c7a..6bc6b51581 100644
--- a/db/migrate/20140825091222_create_splashpages.rb
+++ b/db/migrate/20140825091222_create_splashpages.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateSplashpages < ActiveRecord::Migration
+class CreateSplashpages < ActiveRecord::Migration[4.2]
   def change
     create_table :splashpages do |t|
       t.integer :conference_id
diff --git a/db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb b/db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb
index 6e97581e49..3e03e476f6 100644
--- a/db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb
+++ b/db/migrate/20140825093132_move_splashpage_attributes_from_conference_to_splashpage.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MoveSplashpageAttributesFromConferenceToSplashpage < ActiveRecord::Migration
+class MoveSplashpageAttributesFromConferenceToSplashpage < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20140930092923_move_sponsor_email_to_contact.rb b/db/migrate/20140930092923_move_sponsor_email_to_contact.rb
index 1f598cd339..805f03fc95 100644
--- a/db/migrate/20140930092923_move_sponsor_email_to_contact.rb
+++ b/db/migrate/20140930092923_move_sponsor_email_to_contact.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MoveSponsorEmailToContact < ActiveRecord::Migration
+class MoveSponsorEmailToContact < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20141031225545_add_require_handicapped_access_to_questions.rb b/db/migrate/20141031225545_add_require_handicapped_access_to_questions.rb
index 52695aed63..c599ce92b4 100644
--- a/db/migrate/20141031225545_add_require_handicapped_access_to_questions.rb
+++ b/db/migrate/20141031225545_add_require_handicapped_access_to_questions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddRequireHandicappedAccessToQuestions < ActiveRecord::Migration
+class AddRequireHandicappedAccessToQuestions < ActiveRecord::Migration[4.2]
   class TempRegistration < ActiveRecord::Base
     self.table_name = 'registrations'
 
diff --git a/db/migrate/20141031225606_add_attending_with_partner_to_questions.rb b/db/migrate/20141031225606_add_attending_with_partner_to_questions.rb
index 7f760346d0..ea36170e5f 100644
--- a/db/migrate/20141031225606_add_attending_with_partner_to_questions.rb
+++ b/db/migrate/20141031225606_add_attending_with_partner_to_questions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddAttendingWithPartnerToQuestions < ActiveRecord::Migration
+class AddAttendingWithPartnerToQuestions < ActiveRecord::Migration[4.2]
   class TempRegistration < ActiveRecord::Base
     self.table_name = 'registrations'
 
diff --git a/db/migrate/20141031225620_add_staying_at_suggested_hotel_to_questions.rb b/db/migrate/20141031225620_add_staying_at_suggested_hotel_to_questions.rb
index 3ff4ecb5ab..de1b290f6a 100644
--- a/db/migrate/20141031225620_add_staying_at_suggested_hotel_to_questions.rb
+++ b/db/migrate/20141031225620_add_staying_at_suggested_hotel_to_questions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddStayingAtSuggestedHotelToQuestions < ActiveRecord::Migration
+class AddStayingAtSuggestedHotelToQuestions < ActiveRecord::Migration[4.2]
   class TempRegistration < ActiveRecord::Base
     self.table_name = 'registrations'
 
diff --git a/db/migrate/20141031225635_add_attending_social_events_to_questions.rb b/db/migrate/20141031225635_add_attending_social_events_to_questions.rb
index 75f5a00ec9..3d9d9f4993 100644
--- a/db/migrate/20141031225635_add_attending_social_events_to_questions.rb
+++ b/db/migrate/20141031225635_add_attending_social_events_to_questions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddAttendingSocialEventsToQuestions < ActiveRecord::Migration
+class AddAttendingSocialEventsToQuestions < ActiveRecord::Migration[4.2]
   class TempRegistration < ActiveRecord::Base
     self.table_name = 'registrations'
 
diff --git a/db/migrate/20141103132913_add_username_to_users.rb b/db/migrate/20141103132913_add_username_to_users.rb
index 48b0573c11..15c1c6b0b9 100644
--- a/db/migrate/20141103132913_add_username_to_users.rb
+++ b/db/migrate/20141103132913_add_username_to_users.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddUsernameToUsers < ActiveRecord::Migration
+class AddUsernameToUsers < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :username, :string
     add_index :users, :username, unique: true
diff --git a/db/migrate/20141104131625_generate_username.rb b/db/migrate/20141104131625_generate_username.rb
index e75c808687..1413630f61 100644
--- a/db/migrate/20141104131625_generate_username.rb
+++ b/db/migrate/20141104131625_generate_username.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class GenerateUsername < ActiveRecord::Migration
+class GenerateUsername < ActiveRecord::Migration[4.2]
   class TempUser < ActiveRecord::Base
     self.table_name = 'users'
   end
@@ -10,7 +10,7 @@ def change
       if user.username.blank?
         username = user.email.split('@')[0]
         username += user.id.to_s if TempUser.find_by(username: username)
-        user.update_attributes(username: username)
+        user.update(username: username)
       end
     end
   end
diff --git a/db/migrate/20141106141750_add_is_disabled_flag_to_user.rb b/db/migrate/20141106141750_add_is_disabled_flag_to_user.rb
index 6f3fa63c58..ab2909b52b 100644
--- a/db/migrate/20141106141750_add_is_disabled_flag_to_user.rb
+++ b/db/migrate/20141106141750_add_is_disabled_flag_to_user.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIsDisabledFlagToUser < ActiveRecord::Migration
+class AddIsDisabledFlagToUser < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :is_disabled, :boolean, default: false
   end
diff --git a/db/migrate/20141109172204_set_room_public_default_to_false.rb b/db/migrate/20141109172204_set_room_public_default_to_false.rb
index 1b1981545b..d6e0dd89c1 100644
--- a/db/migrate/20141109172204_set_room_public_default_to_false.rb
+++ b/db/migrate/20141109172204_set_room_public_default_to_false.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class SetRoomPublicDefaultToFalse < ActiveRecord::Migration
+class SetRoomPublicDefaultToFalse < ActiveRecord::Migration[4.2]
   def change
     change_column :rooms, :public, :boolean, default: false
   end
diff --git a/db/migrate/20141113134103_add_position_to_sponsorship_level.rb b/db/migrate/20141113134103_add_position_to_sponsorship_level.rb
index 3683964d5e..505ce26c0a 100644
--- a/db/migrate/20141113134103_add_position_to_sponsorship_level.rb
+++ b/db/migrate/20141113134103_add_position_to_sponsorship_level.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddPositionToSponsorshipLevel < ActiveRecord::Migration
+class AddPositionToSponsorshipLevel < ActiveRecord::Migration[4.2]
   def change
     add_column :sponsorship_levels, :position, :integer
   end
diff --git a/db/migrate/20141117214230_move_banner_description_to_conference.rb b/db/migrate/20141117214230_move_banner_description_to_conference.rb
index c2f30765ce..ed95f0b02a 100644
--- a/db/migrate/20141117214230_move_banner_description_to_conference.rb
+++ b/db/migrate/20141117214230_move_banner_description_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MoveBannerDescriptionToConference < ActiveRecord::Migration
+class MoveBannerDescriptionToConference < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb b/db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb
index e4701a1221..fdf50eb662 100644
--- a/db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb
+++ b/db/migrate/20141117222919_drop_splash_descriptions_and_photo.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class DropSplashDescriptionsAndPhoto < ActiveRecord::Migration
+class DropSplashDescriptionsAndPhoto < ActiveRecord::Migration[4.2]
   def change
     remove_column :splashpages, :ticket_description
     remove_column :splashpages, :sponsor_description
diff --git a/db/migrate/20141118143700_add_address_fields_to_venue.rb b/db/migrate/20141118143700_add_address_fields_to_venue.rb
index c91d6033eb..641dd40f12 100644
--- a/db/migrate/20141118143700_add_address_fields_to_venue.rb
+++ b/db/migrate/20141118143700_add_address_fields_to_venue.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddAddressFieldsToVenue < ActiveRecord::Migration
+class AddAddressFieldsToVenue < ActiveRecord::Migration[4.2]
   def change
     add_column :venues, :street, :string
     add_column :venues, :postalcode, :integer
diff --git a/db/migrate/20141118150427_cleanup_venue.rb b/db/migrate/20141118150427_cleanup_venue.rb
index 31cb86fd42..0f82a51765 100644
--- a/db/migrate/20141118150427_cleanup_venue.rb
+++ b/db/migrate/20141118150427_cleanup_venue.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CleanupVenue < ActiveRecord::Migration
+class CleanupVenue < ActiveRecord::Migration[4.2]
   def change
     change_column :venues, :name, :string
     remove_column :venues, :offline_map_url, :string
diff --git a/db/migrate/20141118153918_change_venue_conference_association.rb b/db/migrate/20141118153918_change_venue_conference_association.rb
index 26096c8272..530cc2c9c7 100644
--- a/db/migrate/20141118153918_change_venue_conference_association.rb
+++ b/db/migrate/20141118153918_change_venue_conference_association.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangeVenueConferenceAssociation < ActiveRecord::Migration
+class ChangeVenueConferenceAssociation < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20141118162030_change_lodging_association_to_conference.rb b/db/migrate/20141118162030_change_lodging_association_to_conference.rb
index 0b91b58741..6b3125c656 100644
--- a/db/migrate/20141118162030_change_lodging_association_to_conference.rb
+++ b/db/migrate/20141118162030_change_lodging_association_to_conference.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangeLodgingAssociationToConference < ActiveRecord::Migration
+class ChangeLodgingAssociationToConference < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20141120205757_remove_public_from_room.rb b/db/migrate/20141120205757_remove_public_from_room.rb
index f96aa84c95..710f1beea7 100644
--- a/db/migrate/20141120205757_remove_public_from_room.rb
+++ b/db/migrate/20141120205757_remove_public_from_room.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemovePublicFromRoom < ActiveRecord::Migration
+class RemovePublicFromRoom < ActiveRecord::Migration[4.2]
   def change
     remove_column :rooms, :public, :boolean, default: false
   end
diff --git a/db/migrate/20141121102656_remove_description_from_call_for_paper.rb b/db/migrate/20141121102656_remove_description_from_call_for_paper.rb
index fc6282a5db..632246698c 100644
--- a/db/migrate/20141121102656_remove_description_from_call_for_paper.rb
+++ b/db/migrate/20141121102656_remove_description_from_call_for_paper.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveDescriptionFromCallForPaper < ActiveRecord::Migration
+class RemoveDescriptionFromCallForPaper < ActiveRecord::Migration[4.2]
   def change
     remove_column :call_for_papers, :description, :text
   end
diff --git a/db/migrate/20141127161313_add_is_highlight_in_events.rb b/db/migrate/20141127161313_add_is_highlight_in_events.rb
index 694e0ea227..aa82eb77df 100644
--- a/db/migrate/20141127161313_add_is_highlight_in_events.rb
+++ b/db/migrate/20141127161313_add_is_highlight_in_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIsHighlightInEvents < ActiveRecord::Migration
+class AddIsHighlightInEvents < ActiveRecord::Migration[4.2]
   def change
     add_column :events, :is_highlight, :boolean, default: false
   end
diff --git a/db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb b/db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb
index a90b5c5306..8ab3e3d840 100644
--- a/db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb
+++ b/db/migrate/20141128073306_migrate_data_remove_column_include_cfp_in_splash_add_column_include_cfp.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MigrateDataRemoveColumnIncludeCfpInSplashAddColumnIncludeCfp < ActiveRecord::Migration
+class MigrateDataRemoveColumnIncludeCfpInSplashAddColumnIncludeCfp < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20141130182139_drop_table_event_attachments.rb b/db/migrate/20141130182139_drop_table_event_attachments.rb
index dbe856c1f8..b8c9f38414 100644
--- a/db/migrate/20141130182139_drop_table_event_attachments.rb
+++ b/db/migrate/20141130182139_drop_table_event_attachments.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class DropTableEventAttachments < ActiveRecord::Migration
+class DropTableEventAttachments < ActiveRecord::Migration[4.2]
   def change
     drop_table :event_attachments
   end
diff --git a/db/migrate/20150304135935_add_created_atto_qanswer.rb b/db/migrate/20150304135935_add_created_atto_qanswer.rb
index e4a319e20c..fa9a4bea69 100644
--- a/db/migrate/20150304135935_add_created_atto_qanswer.rb
+++ b/db/migrate/20150304135935_add_created_atto_qanswer.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddCreatedAttoQanswer < ActiveRecord::Migration
+class AddCreatedAttoQanswer < ActiveRecord::Migration[4.2]
   def change
     add_column :qanswers, :created_at, :datetime
     add_column :qanswers, :updated_at, :datetime
diff --git a/db/migrate/20150415121038_add_description_to_event_type.rb b/db/migrate/20150415121038_add_description_to_event_type.rb
index 3979d574c1..e1bbd1721e 100644
--- a/db/migrate/20150415121038_add_description_to_event_type.rb
+++ b/db/migrate/20150415121038_add_description_to_event_type.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddDescriptionToEventType < ActiveRecord::Migration
+class AddDescriptionToEventType < ActiveRecord::Migration[4.2]
   def change
     add_column :event_types, :description, :string
   end
diff --git a/db/migrate/20150417050953_add_url_to_commercial.rb b/db/migrate/20150417050953_add_url_to_commercial.rb
index 4ab69724e7..357b4a6d69 100644
--- a/db/migrate/20150417050953_add_url_to_commercial.rb
+++ b/db/migrate/20150417050953_add_url_to_commercial.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddUrlToCommercial < ActiveRecord::Migration
+class AddUrlToCommercial < ActiveRecord::Migration[4.2]
   class TempCommercial < ActiveRecord::Base
     self.table_name = 'commercials'
   end
diff --git a/db/migrate/20150929142405_change_postalcode_format_in_venues.rb b/db/migrate/20150929142405_change_postalcode_format_in_venues.rb
index 28f92c085c..8cf4617ac3 100644
--- a/db/migrate/20150929142405_change_postalcode_format_in_venues.rb
+++ b/db/migrate/20150929142405_change_postalcode_format_in_venues.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangePostalcodeFormatInVenues < ActiveRecord::Migration
+class ChangePostalcodeFormatInVenues < ActiveRecord::Migration[4.2]
   def up
     change_column :venues, :postalcode, :string
   end
diff --git a/db/migrate/20151005161518_rename_templates_in_email_settings.rb b/db/migrate/20151005161518_rename_templates_in_email_settings.rb
index 848cd9a349..16c9c9434d 100644
--- a/db/migrate/20151005161518_rename_templates_in_email_settings.rb
+++ b/db/migrate/20151005161518_rename_templates_in_email_settings.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RenameTemplatesInEmailSettings < ActiveRecord::Migration
+class RenameTemplatesInEmailSettings < ActiveRecord::Migration[4.2]
   def change
     rename_column :email_settings, :registration_email_template, :registration_body
     rename_column :email_settings, :accepted_email_template, :accepted_body
diff --git a/db/migrate/20151018152439_create_programs_table.rb b/db/migrate/20151018152439_create_programs_table.rb
index 6024b7d4fb..54e6f43a50 100644
--- a/db/migrate/20151018152439_create_programs_table.rb
+++ b/db/migrate/20151018152439_create_programs_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateProgramsTable < ActiveRecord::Migration
+class CreateProgramsTable < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20151018154513_rename_conference_id_to_program_id_in_events_tracks_difficulty_levels.rb b/db/migrate/20151018154513_rename_conference_id_to_program_id_in_events_tracks_difficulty_levels.rb
index e5149a33ab..6521f4adf6 100644
--- a/db/migrate/20151018154513_rename_conference_id_to_program_id_in_events_tracks_difficulty_levels.rb
+++ b/db/migrate/20151018154513_rename_conference_id_to_program_id_in_events_tracks_difficulty_levels.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RenameConferenceIdToProgramIdInEventsTracksDifficultyLevels < ActiveRecord::Migration
+class RenameConferenceIdToProgramIdInEventsTracksDifficultyLevels < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end
diff --git a/db/migrate/20151021113015_rename_email_settings_with_cfp_and_program.rb b/db/migrate/20151021113015_rename_email_settings_with_cfp_and_program.rb
index b43c6c23c4..ef7271eb61 100644
--- a/db/migrate/20151021113015_rename_email_settings_with_cfp_and_program.rb
+++ b/db/migrate/20151021113015_rename_email_settings_with_cfp_and_program.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RenameEmailSettingsWithCfpAndProgram < ActiveRecord::Migration
+class RenameEmailSettingsWithCfpAndProgram < ActiveRecord::Migration[4.2]
   def change
     rename_column :email_settings, :send_on_call_for_papers_schedule_public, :send_on_program_schedule_public
     rename_column :email_settings, :call_for_papers_schedule_public_body, :program_schedule_public_body
diff --git a/db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb b/db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb
index cab34a841b..271a81320b 100644
--- a/db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb
+++ b/db/migrate/20151031092713_change_conference_id_to_venue_id_in_rooms.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangeConferenceIdToVenueIdInRooms < ActiveRecord::Migration
+class ChangeConferenceIdToVenueIdInRooms < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
 
diff --git a/db/migrate/20160201221411_add_registration_limit_to_conferences.rb b/db/migrate/20160201221411_add_registration_limit_to_conferences.rb
index 82aa4df726..01c7bb87b5 100644
--- a/db/migrate/20160201221411_add_registration_limit_to_conferences.rb
+++ b/db/migrate/20160201221411_add_registration_limit_to_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddRegistrationLimitToConferences < ActiveRecord::Migration
+class AddRegistrationLimitToConferences < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :registration_limit, :integer, default: 0
   end
diff --git a/db/migrate/20160226133808_rename_roles_users_to_users_roles.rb b/db/migrate/20160226133808_rename_roles_users_to_users_roles.rb
index ca8af270e4..947cb1f464 100644
--- a/db/migrate/20160226133808_rename_roles_users_to_users_roles.rb
+++ b/db/migrate/20160226133808_rename_roles_users_to_users_roles.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RenameRolesUsersToUsersRoles < ActiveRecord::Migration
+class RenameRolesUsersToUsersRoles < ActiveRecord::Migration[4.2]
   def change
     rename_table :roles_users, :users_roles
   end
diff --git a/db/migrate/20160309182642_remove_social_events_table.rb b/db/migrate/20160309182642_remove_social_events_table.rb
index 6e4505a752..0ab05bbc5d 100644
--- a/db/migrate/20160309182642_remove_social_events_table.rb
+++ b/db/migrate/20160309182642_remove_social_events_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveSocialEventsTable < ActiveRecord::Migration
+class RemoveSocialEventsTable < ActiveRecord::Migration[4.2]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
 
diff --git a/db/migrate/20160309182655_remove_dietary_choices_table.rb b/db/migrate/20160309182655_remove_dietary_choices_table.rb
index 1b25f6e982..8a4689249f 100644
--- a/db/migrate/20160309182655_remove_dietary_choices_table.rb
+++ b/db/migrate/20160309182655_remove_dietary_choices_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveDietaryChoicesTable < ActiveRecord::Migration
+class RemoveDietaryChoicesTable < ActiveRecord::Migration[4.2]
   class TempDietaryChoice < ActiveRecord::Base
     self.table_name = 'dietary_choices'
 
diff --git a/db/migrate/20160309183052_remove_html_export_path_from_conferences.rb b/db/migrate/20160309183052_remove_html_export_path_from_conferences.rb
index 01fbd3a78e..9290754d80 100644
--- a/db/migrate/20160309183052_remove_html_export_path_from_conferences.rb
+++ b/db/migrate/20160309183052_remove_html_export_path_from_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveHtmlExportPathFromConferences < ActiveRecord::Migration
+class RemoveHtmlExportPathFromConferences < ActiveRecord::Migration[4.2]
   def change
     remove_column :conferences, :html_export_path, :string
   end
diff --git a/db/migrate/20160320220630_add_languages_to_program.rb b/db/migrate/20160320220630_add_languages_to_program.rb
index 49be193f6a..13b273aac0 100644
--- a/db/migrate/20160320220630_add_languages_to_program.rb
+++ b/db/migrate/20160320220630_add_languages_to_program.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddLanguagesToProgram < ActiveRecord::Migration
+class AddLanguagesToProgram < ActiveRecord::Migration[4.2]
   def change
     add_column :programs, :languages, :string
   end
diff --git a/db/migrate/20160323154504_add_max_attendees_to_events.rb b/db/migrate/20160323154504_add_max_attendees_to_events.rb
index bb3e770f67..a0ffe96795 100644
--- a/db/migrate/20160323154504_add_max_attendees_to_events.rb
+++ b/db/migrate/20160323154504_add_max_attendees_to_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddMaxAttendeesToEvents < ActiveRecord::Migration
+class AddMaxAttendeesToEvents < ActiveRecord::Migration[4.2]
   def change
     add_column :events, :max_attendees, :integer
   end
diff --git a/db/migrate/20160326075326_add_attended_to_events_registrations.rb b/db/migrate/20160326075326_add_attended_to_events_registrations.rb
index 562cdf3461..4b82bfc5cd 100644
--- a/db/migrate/20160326075326_add_attended_to_events_registrations.rb
+++ b/db/migrate/20160326075326_add_attended_to_events_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddAttendedToEventsRegistrations < ActiveRecord::Migration
+class AddAttendedToEventsRegistrations < ActiveRecord::Migration[4.2]
   def change
     add_column :events_registrations, :attended, :boolean, default: false, null: false
   end
diff --git a/db/migrate/20160403214841_add_id_and_created_at_to_events_registrations.rb b/db/migrate/20160403214841_add_id_and_created_at_to_events_registrations.rb
index 6e1e7200dc..8f0abe3cfa 100644
--- a/db/migrate/20160403214841_add_id_and_created_at_to_events_registrations.rb
+++ b/db/migrate/20160403214841_add_id_and_created_at_to_events_registrations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIdAndCreatedAtToEventsRegistrations < ActiveRecord::Migration
+class AddIdAndCreatedAtToEventsRegistrations < ActiveRecord::Migration[4.2]
   def change
     add_column :events_registrations, :id, :primary_key
     add_column :events_registrations, :created_at, :datetime
diff --git a/db/migrate/20160427101444_remove_photos.rb b/db/migrate/20160427101444_remove_photos.rb
index d1f93a63ee..1d3c3cfc98 100644
--- a/db/migrate/20160427101444_remove_photos.rb
+++ b/db/migrate/20160427101444_remove_photos.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemovePhotos < ActiveRecord::Migration
+class RemovePhotos < ActiveRecord::Migration[4.2]
   def change
     drop_table :photos do |t|
       t.text :description
diff --git a/db/migrate/20160427104236_add_pictures.rb b/db/migrate/20160427104236_add_pictures.rb
index dcfa6a237b..aa9c835190 100644
--- a/db/migrate/20160427104236_add_pictures.rb
+++ b/db/migrate/20160427104236_add_pictures.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddPictures < ActiveRecord::Migration
+class AddPictures < ActiveRecord::Migration[4.2]
   def change
     add_column :conferences, :picture, :string
     add_column :lodgings, :picture, :string
diff --git a/db/migrate/20160427104237_add_blind_voting_to_programs.rb b/db/migrate/20160427104237_add_blind_voting_to_programs.rb
index f92be56dfb..abdb1dfcbd 100644
--- a/db/migrate/20160427104237_add_blind_voting_to_programs.rb
+++ b/db/migrate/20160427104237_add_blind_voting_to_programs.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddBlindVotingToPrograms < ActiveRecord::Migration
+class AddBlindVotingToPrograms < ActiveRecord::Migration[4.2]
   def change
     add_column :programs, :blind_voting, :boolean, default: false
   end
diff --git a/db/migrate/20160427104238_add_voting_dates_to_program.rb b/db/migrate/20160427104238_add_voting_dates_to_program.rb
index 32c2071488..f1ab43a945 100644
--- a/db/migrate/20160427104238_add_voting_dates_to_program.rb
+++ b/db/migrate/20160427104238_add_voting_dates_to_program.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddVotingDatesToProgram < ActiveRecord::Migration
+class AddVotingDatesToProgram < ActiveRecord::Migration[4.2]
   def change
     add_column :programs, :voting_start_date, :datetime
     add_column :programs, :voting_end_date, :datetime
diff --git a/db/migrate/20160524050538_add_conference_id_to_versions.rb b/db/migrate/20160524050538_add_conference_id_to_versions.rb
index e6c8a41196..98e8453a22 100644
--- a/db/migrate/20160524050538_add_conference_id_to_versions.rb
+++ b/db/migrate/20160524050538_add_conference_id_to_versions.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddConferenceIdToVersions < ActiveRecord::Migration
+class AddConferenceIdToVersions < ActiveRecord::Migration[4.2]
   def change
     add_column :versions, :conference_id, :integer
   end
diff --git a/db/migrate/20160524104006_remove_unused_logo_columns_and_use_difficulty_levels_from_conferences.rb b/db/migrate/20160524104006_remove_unused_logo_columns_and_use_difficulty_levels_from_conferences.rb
index fb3cedf615..ba9514c378 100644
--- a/db/migrate/20160524104006_remove_unused_logo_columns_and_use_difficulty_levels_from_conferences.rb
+++ b/db/migrate/20160524104006_remove_unused_logo_columns_and_use_difficulty_levels_from_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveUnusedLogoColumnsAndUseDifficultyLevelsFromConferences < ActiveRecord::Migration
+class RemoveUnusedLogoColumnsAndUseDifficultyLevelsFromConferences < ActiveRecord::Migration[4.2]
   def up
     remove_column :conferences, :logo_updated_at
     remove_column :conferences, :logo_file_size
diff --git a/db/migrate/20160524104501_remove_unused_logo_columns_from_sponsors.rb b/db/migrate/20160524104501_remove_unused_logo_columns_from_sponsors.rb
index 1770d3539a..84347d3ce5 100644
--- a/db/migrate/20160524104501_remove_unused_logo_columns_from_sponsors.rb
+++ b/db/migrate/20160524104501_remove_unused_logo_columns_from_sponsors.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveUnusedLogoColumnsFromSponsors < ActiveRecord::Migration
+class RemoveUnusedLogoColumnsFromSponsors < ActiveRecord::Migration[4.2]
   def up
     remove_column :sponsors, :logo_updated_at
     remove_column :sponsors, :logo_file_size
diff --git a/db/migrate/20160524104805_remove_logo_and_progress_and_time_slots_from_events.rb b/db/migrate/20160524104805_remove_logo_and_progress_and_time_slots_from_events.rb
index eccfffb202..fd8c1f2408 100644
--- a/db/migrate/20160524104805_remove_logo_and_progress_and_time_slots_from_events.rb
+++ b/db/migrate/20160524104805_remove_logo_and_progress_and_time_slots_from_events.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveLogoAndProgressAndTimeSlotsFromEvents < ActiveRecord::Migration
+class RemoveLogoAndProgressAndTimeSlotsFromEvents < ActiveRecord::Migration[4.2]
   def up
     remove_column :events, :logo_file_name
     remove_column :events, :logo_updated_at
diff --git a/db/migrate/20160606040848_create_payments.rb b/db/migrate/20160606040848_create_payments.rb
index 6db6f4c2d3..71dc8b0d23 100644
--- a/db/migrate/20160606040848_create_payments.rb
+++ b/db/migrate/20160606040848_create_payments.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreatePayments < ActiveRecord::Migration
+class CreatePayments < ActiveRecord::Migration[4.2]
   def change
     create_table :payments do |t|
       t.string :last4
diff --git a/db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb b/db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb
index 3c3f599787..a2755924f2 100644
--- a/db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb
+++ b/db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddPaymentIdToTicketPurchases < ActiveRecord::Migration
+class AddPaymentIdToTicketPurchases < ActiveRecord::Migration[4.2]
   def change
     add_column :ticket_purchases, :payment_id, :integer
   end
diff --git a/db/migrate/20160614145614_add_id_to_users_roles.rb b/db/migrate/20160614145614_add_id_to_users_roles.rb
index 59b8936aa1..bc5e42c1ea 100644
--- a/db/migrate/20160614145614_add_id_to_users_roles.rb
+++ b/db/migrate/20160614145614_add_id_to_users_roles.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIdToUsersRoles < ActiveRecord::Migration
+class AddIdToUsersRoles < ActiveRecord::Migration[4.2]
   def change
     add_column :users_roles, :id, :primary_key
   end
diff --git a/db/migrate/20160624151257_remove_unused_photo_columns_from_venues.rb b/db/migrate/20160624151257_remove_unused_photo_columns_from_venues.rb
index c0e29eb126..7a88ae3e8b 100644
--- a/db/migrate/20160624151257_remove_unused_photo_columns_from_venues.rb
+++ b/db/migrate/20160624151257_remove_unused_photo_columns_from_venues.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class RemoveUnusedPhotoColumnsFromVenues < ActiveRecord::Migration
+class RemoveUnusedPhotoColumnsFromVenues < ActiveRecord::Migration[4.2]
   def up
     remove_column :venues, :photo_updated_at
     remove_column :venues, :photo_file_size
diff --git a/db/migrate/20160704091928_create_schedules.rb b/db/migrate/20160704091928_create_schedules.rb
index 184046ccc8..87f89972e3 100644
--- a/db/migrate/20160704091928_create_schedules.rb
+++ b/db/migrate/20160704091928_create_schedules.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateSchedules < ActiveRecord::Migration
+class CreateSchedules < ActiveRecord::Migration[5.0]
   def change
     create_table :schedules do |t|
       t.belongs_to :program, index: true
diff --git a/db/migrate/20160704092023_create_event_schedules.rb b/db/migrate/20160704092023_create_event_schedules.rb
index 8158b277af..76f4fe08b0 100644
--- a/db/migrate/20160704092023_create_event_schedules.rb
+++ b/db/migrate/20160704092023_create_event_schedules.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateEventSchedules < ActiveRecord::Migration
+class CreateEventSchedules < ActiveRecord::Migration[5.0]
   def change
     create_table :event_schedules do |t|
       t.belongs_to :event, index: true
diff --git a/db/migrate/20160815094215_add_times_to_conferences.rb b/db/migrate/20160815094215_add_times_to_conferences.rb
index 70630f01da..3ce705f597 100644
--- a/db/migrate/20160815094215_add_times_to_conferences.rb
+++ b/db/migrate/20160815094215_add_times_to_conferences.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddTimesToConferences < ActiveRecord::Migration
+class AddTimesToConferences < ActiveRecord::Migration[5.0]
   def change
     add_column :conferences, :start_hour, :integer, default: 9
     add_column :conferences, :end_hour, :integer, default: 20
diff --git a/db/migrate/20160815140302_add_index_to_event_schedule.rb b/db/migrate/20160815140302_add_index_to_event_schedule.rb
index 373265fee4..47aaa0d08c 100644
--- a/db/migrate/20160815140302_add_index_to_event_schedule.rb
+++ b/db/migrate/20160815140302_add_index_to_event_schedule.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddIndexToEventSchedule < ActiveRecord::Migration
+class AddIndexToEventSchedule < ActiveRecord::Migration[5.0]
   def change
     add_index :event_schedules, [:event_id, :schedule_id], unique: true
   end
diff --git a/db/migrate/20170129075434_create_resources_table.rb b/db/migrate/20170129075434_create_resources_table.rb
index b3aec9df0a..b5fe8cf9e2 100644
--- a/db/migrate/20170129075434_create_resources_table.rb
+++ b/db/migrate/20170129075434_create_resources_table.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateResourcesTable < ActiveRecord::Migration
+class CreateResourcesTable < ActiveRecord::Migration[5.0]
   def change
     create_table :resources do |t|
       t.string :name
diff --git a/db/migrate/20170213145807_change_email_public_from_users.rb b/db/migrate/20170213145807_change_email_public_from_users.rb
index adac23107c..185cbf8a74 100644
--- a/db/migrate/20170213145807_change_email_public_from_users.rb
+++ b/db/migrate/20170213145807_change_email_public_from_users.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class ChangeEmailPublicFromUsers < ActiveRecord::Migration
+class ChangeEmailPublicFromUsers < ActiveRecord::Migration[5.0]
   def up
     change_column_default :users, :email_public, true
   end
diff --git a/db/migrate/20170302145716_add_schedule_interval_to_programs.rb b/db/migrate/20170302145716_add_schedule_interval_to_programs.rb
index 1cc8bdcc7a..459cdb0e42 100644
--- a/db/migrate/20170302145716_add_schedule_interval_to_programs.rb
+++ b/db/migrate/20170302145716_add_schedule_interval_to_programs.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddScheduleIntervalToPrograms < ActiveRecord::Migration
+class AddScheduleIntervalToPrograms < ActiveRecord::Migration[5.0]
   def change
     add_column :programs, :schedule_interval, :integer, default: 15, null: false
   end
diff --git a/db/migrate/20170419132148_add_week_to_ticket_purchases.rb b/db/migrate/20170419132148_add_week_to_ticket_purchases.rb
index 8fe0be2cdc..9559656a34 100644
--- a/db/migrate/20170419132148_add_week_to_ticket_purchases.rb
+++ b/db/migrate/20170419132148_add_week_to_ticket_purchases.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class AddWeekToTicketPurchases < ActiveRecord::Migration
+class AddWeekToTicketPurchases < ActiveRecord::Migration[5.0]
   class TmpTicketPurchase < ActiveRecord::Base
     self.table_name = 'ticket_purchases'
   end
diff --git a/db/migrate/20170529215453_create_organizations.rb b/db/migrate/20170529215453_create_organizations.rb
index ffa424cc5e..e3fcb270d7 100644
--- a/db/migrate/20170529215453_create_organizations.rb
+++ b/db/migrate/20170529215453_create_organizations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class CreateOrganizations < ActiveRecord::Migration
+class CreateOrganizations < ActiveRecord::Migration[5.0]
   def change
     create_table :organizations do |t|
       t.string :name, null: false
diff --git a/db/migrate/20170531094819_move_conferences_to_organizations.rb b/db/migrate/20170531094819_move_conferences_to_organizations.rb
index 7f7e776cbc..c76696cc93 100644
--- a/db/migrate/20170531094819_move_conferences_to_organizations.rb
+++ b/db/migrate/20170531094819_move_conferences_to_organizations.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class MoveConferencesToOrganizations < ActiveRecord::Migration
+class MoveConferencesToOrganizations < ActiveRecord::Migration[5.0]
   class TempConference < ActiveRecord::Base
     self.table_name = 'conferences'
   end