diff --git a/lib/active_storage_validations/marcel_extensor.rb b/lib/active_storage_validations/marcel_extensor.rb
index 53f3dce..7db8fe8 100644
--- a/lib/active_storage_validations/marcel_extensor.rb
+++ b/lib/active_storage_validations/marcel_extensor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Marcel::MimeType.extend "application/x-rar-compressed", parents: %(application/x-rar)
 Marcel::MimeType.extend "audio/x-hx-aac-adts", parents: %(audio/x-aac)
 Marcel::MimeType.extend "audio/x-m4a", parents: %(audio/mp4)
diff --git a/lib/active_storage_validations/matchers/shared/asv_active_storageable.rb b/lib/active_storage_validations/matchers/shared/asv_active_storageable.rb
index 9ffffe2..57cc578 100644
--- a/lib/active_storage_validations/matchers/shared/asv_active_storageable.rb
+++ b/lib/active_storage_validations/matchers/shared/asv_active_storageable.rb
@@ -1,4 +1,6 @@
-require "active_support/concern"
+# frozen_string_literal: true
+
+require 'active_support/concern'
 
 module ActiveStorageValidations
   module Matchers
diff --git a/lib/active_storage_validations/matchers/shared/asv_allow_blankable.rb b/lib/active_storage_validations/matchers/shared/asv_allow_blankable.rb
index 9167bb8..3048b41 100644
--- a/lib/active_storage_validations/matchers/shared/asv_allow_blankable.rb
+++ b/lib/active_storage_validations/matchers/shared/asv_allow_blankable.rb
@@ -1,4 +1,6 @@
-require "active_support/concern"
+# frozen_string_literal: true
+
+require 'active_support/concern'
 
 module ActiveStorageValidations
   module Matchers
diff --git a/lib/active_storage_validations/matchers/shared/asv_attachable.rb b/lib/active_storage_validations/matchers/shared/asv_attachable.rb
index 9889eeb..4bcf613 100644
--- a/lib/active_storage_validations/matchers/shared/asv_attachable.rb
+++ b/lib/active_storage_validations/matchers/shared/asv_attachable.rb
@@ -1,6 +1,12 @@
+# frozen_string_literal: true
+
+require 'active_support/concern'
+
 module ActiveStorageValidations
   module Matchers
     module ASVAttachable
+      extend ActiveSupport::Concern
+
       private
 
       def attach_file(file = dummy_file)
diff --git a/lib/active_storage_validations/matchers/shared/asv_contextable.rb b/lib/active_storage_validations/matchers/shared/asv_contextable.rb
index 4812e51..0a7f4de 100644
--- a/lib/active_storage_validations/matchers/shared/asv_contextable.rb
+++ b/lib/active_storage_validations/matchers/shared/asv_contextable.rb
@@ -1,4 +1,6 @@
-require "active_support/concern"
+# frozen_string_literal: true
+
+require 'active_support/concern'
 
 module ActiveStorageValidations
   module Matchers
diff --git a/lib/active_storage_validations/matchers/shared/asv_messageable.rb b/lib/active_storage_validations/matchers/shared/asv_messageable.rb
index 07ab635..feac24c 100644
--- a/lib/active_storage_validations/matchers/shared/asv_messageable.rb
+++ b/lib/active_storage_validations/matchers/shared/asv_messageable.rb
@@ -1,4 +1,6 @@
-require "active_support/concern"
+# frozen_string_literal: true
+
+require 'active_support/concern'
 
 module ActiveStorageValidations
   module Matchers
diff --git a/lib/active_storage_validations/matchers/shared/asv_rspecable.rb b/lib/active_storage_validations/matchers/shared/asv_rspecable.rb
index fb1afc2..7a640c0 100644
--- a/lib/active_storage_validations/matchers/shared/asv_rspecable.rb
+++ b/lib/active_storage_validations/matchers/shared/asv_rspecable.rb
@@ -1,4 +1,6 @@
-require "active_support/concern"
+# frozen_string_literal: true
+
+require 'active_support/concern'
 
 module ActiveStorageValidations
   module Matchers
diff --git a/lib/active_storage_validations/matchers/shared/asv_validatable.rb b/lib/active_storage_validations/matchers/shared/asv_validatable.rb
index f519f92..554ef16 100644
--- a/lib/active_storage_validations/matchers/shared/asv_validatable.rb
+++ b/lib/active_storage_validations/matchers/shared/asv_validatable.rb
@@ -1,4 +1,6 @@
-require "active_support/concern"
+# frozen_string_literal: true
+
+require 'active_support/concern'
 
 module ActiveStorageValidations
   module Matchers
diff --git a/lib/active_storage_validations/shared/asv_active_storageable.rb b/lib/active_storage_validations/shared/asv_active_storageable.rb
index 10fe863..aa6f33c 100644
--- a/lib/active_storage_validations/shared/asv_active_storageable.rb
+++ b/lib/active_storage_validations/shared/asv_active_storageable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveStorageValidations
   # ActiveStorageValidations::ASVActiveStorageable
   #
diff --git a/lib/active_storage_validations/shared/asv_attachable.rb b/lib/active_storage_validations/shared/asv_attachable.rb
index 1911f6d..60bbab9 100644
--- a/lib/active_storage_validations/shared/asv_attachable.rb
+++ b/lib/active_storage_validations/shared/asv_attachable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative "../metadata"
 
 module ActiveStorageValidations
diff --git a/lib/active_storage_validations/shared/asv_errorable.rb b/lib/active_storage_validations/shared/asv_errorable.rb
index 7139845..88097dc 100644
--- a/lib/active_storage_validations/shared/asv_errorable.rb
+++ b/lib/active_storage_validations/shared/asv_errorable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveStorageValidations
   module ASVErrorable
     extend ActiveSupport::Concern
diff --git a/lib/active_storage_validations/shared/asv_loggable.rb b/lib/active_storage_validations/shared/asv_loggable.rb
index 5cfc2c9..72eab11 100644
--- a/lib/active_storage_validations/shared/asv_loggable.rb
+++ b/lib/active_storage_validations/shared/asv_loggable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveStorageValidations
   module ASVLoggable
     extend ActiveSupport::Concern
diff --git a/lib/active_storage_validations/shared/asv_optionable.rb b/lib/active_storage_validations/shared/asv_optionable.rb
index 6043100..29f4cc5 100644
--- a/lib/active_storage_validations/shared/asv_optionable.rb
+++ b/lib/active_storage_validations/shared/asv_optionable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveStorageValidations
   # ActiveStorageValidations::ASVOptionable
   #
diff --git a/lib/active_storage_validations/shared/asv_symbolizable.rb b/lib/active_storage_validations/shared/asv_symbolizable.rb
index ac74fa1..c423907 100644
--- a/lib/active_storage_validations/shared/asv_symbolizable.rb
+++ b/lib/active_storage_validations/shared/asv_symbolizable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveStorageValidations
   module ASVSymbolizable
     extend ActiveSupport::Concern