diff --git a/Rakefile b/Rakefile
index 107535f..3975bfa 100755
--- a/Rakefile
+++ b/Rakefile
@@ -7,7 +7,7 @@ end
 
 task 'before_build' do
   signing_key = File.expand_path("~/.gem/librato-private_key.pem")
-  if File.exists?(signing_key)
+  if File.exist?(signing_key)
     puts "Key found: signing gem..."
     ENV['GEM_SIGNING_KEY'] = signing_key
   else
diff --git a/lib/librato/rails/configuration.rb b/lib/librato/rails/configuration.rb
index f326e19..4c09f30 100644
--- a/lib/librato/rails/configuration.rb
+++ b/lib/librato/rails/configuration.rb
@@ -26,7 +26,7 @@ def initialize(options={})
 
       # detect and load configuration from config file or env vars
       def load_configuration
-        if self.config_file && File.exists?(self.config_file)
+        if self.config_file && File.exist?(self.config_file)
           configure_with_config_file
         else
           self.config_by = :environment