diff --git a/spec/generators/views_generator_spec.rb b/spec/generators/views_generator_spec.rb
index 02870d9..da1ca3c 100644
--- a/spec/generators/views_generator_spec.rb
+++ b/spec/generators/views_generator_spec.rb
@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-if defined?(Rails)
+if defined?(::Rails::Railtie)
   require 'rails/generators'
   require 'generators/kaminari/views_generator'
 
diff --git a/spec/helpers/action_view_extension_spec.rb b/spec/helpers/action_view_extension_spec.rb
index 415c659..16b5ee6 100644
--- a/spec/helpers/action_view_extension_spec.rb
+++ b/spec/helpers/action_view_extension_spec.rb
@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-describe 'Kaminari::ActionViewExtension', :if => defined?(Rails) do
+describe 'Kaminari::ActionViewExtension', :if => defined?(::Rails::Railtie) do
   describe '#paginate' do
     before do
       50.times {|i| User.create! :name => "user#{i}"}
diff --git a/spec/helpers/tags_spec.rb b/spec/helpers/tags_spec.rb
index f8c53ef..6092788 100644
--- a/spec/helpers/tags_spec.rb
+++ b/spec/helpers/tags_spec.rb
@@ -3,7 +3,7 @@ include Kaminari::Helpers
 
 describe 'Kaminari::Helpers' do
   describe 'Tag' do
-    describe '#page_url_for', :if => defined?(Rails) do
+    describe '#page_url_for', :if => defined?(::Rails::Railtie) do
       before do
         helper.params[:controller] = 'users'
         helper.params[:action]     = 'index'
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index ab9cd41..e56c315 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -15,7 +15,7 @@ require 'database_cleaner'
 # Simulate a gem providing a subclass of ActiveRecord::Base before the Railtie is loaded.
 require 'fake_gem' if defined? ActiveRecord
 
-if defined? Rails
+if defined? ::Rails::Railtie
   require 'fake_app/rails_app'
 
   require 'rspec/rails'