diff --git a/railties/lib/rails/app_rails_loader.rb b/railties/lib/rails/app_rails_loader.rb
index 56f05b3844d..39d80073337 100644
--- a/railties/lib/rails/app_rails_loader.rb
+++ b/railties/lib/rails/app_rails_loader.rb
@@ -2,6 +2,8 @@ require 'pathname'
 
 module Rails
   module AppRailsLoader
+    extend self
+
     RUBY = Gem.ruby
     EXECUTABLES = ['bin/rails', 'script/rails']
     BUNDLER_WARNING = <<EOS
@@ -26,7 +28,7 @@ generate it and add it to source control:
 
 EOS
 
-    def self.exec_app_rails
+    def exec_app_rails
       original_cwd = Dir.pwd
 
       loop do
@@ -54,7 +56,7 @@ EOS
       end
     end
 
-    def self.find_executable
+    def find_executable
       EXECUTABLES.find { |exe| File.file?(exe) }
     end
   end
diff --git a/railties/test/app_rails_loader_test.rb b/railties/test/app_rails_loader_test.rb
index 1d3b80253a2..d4885447e6d 100644
--- a/railties/test/app_rails_loader_test.rb
+++ b/railties/test/app_rails_loader_test.rb
@@ -3,13 +3,27 @@ require 'abstract_unit'
 require 'rails/app_rails_loader'
 
 class AppRailsLoaderTest < ActiveSupport::TestCase
+  def loader
+    @loader ||= Class.new do
+      extend Rails::AppRailsLoader
+
+      def self.exec_arguments
+        @exec_arguments
+      end
+
+      def self.exec(*args)
+        @exec_arguments = args
+      end
+    end
+  end
+
   def write(filename, contents=nil)
     FileUtils.mkdir_p(File.dirname(filename))
     File.write(filename, contents)
   end
 
   def expects_exec(exe)
-    Rails::AppRailsLoader.expects(:exec).with(Rails::AppRailsLoader::RUBY, exe)
+    assert_equal [Rails::AppRailsLoader::RUBY, exe], loader.exec_arguments
   end
 
   setup do
@@ -22,30 +36,30 @@ class AppRailsLoaderTest < ActiveSupport::TestCase
     exe = "#{script_dir}/rails"
 
     test "is not in a Rails application if #{exe} is not found in the current or parent directories" do
-      File.stubs(:file?).with('bin/rails').returns(false)
-      File.stubs(:file?).with('script/rails').returns(false)
+      def loader.find_executables; end
 
-      assert !Rails::AppRailsLoader.exec_app_rails
+      assert !loader.exec_app_rails
     end
 
     test "is not in a Rails application if #{exe} exists but is a folder" do
       FileUtils.mkdir_p(exe)
 
-      assert !Rails::AppRailsLoader.exec_app_rails
+      assert !loader.exec_app_rails
     end
 
     ['APP_PATH', 'ENGINE_PATH'].each do |keyword|
       test "is in a Rails application if #{exe} exists and contains #{keyword}" do
         write exe, keyword
 
+        loader.exec_app_rails
+
         expects_exec exe
-        Rails::AppRailsLoader.exec_app_rails
       end
 
       test "is not in a Rails application if #{exe} exists but doesn't contain #{keyword}" do
         write exe
 
-        assert !Rails::AppRailsLoader.exec_app_rails
+        assert !loader.exec_app_rails
       end
 
       test "is in a Rails application if parent directory has #{exe} containing #{keyword} and chdirs to the root directory" do
@@ -54,8 +68,9 @@ class AppRailsLoaderTest < ActiveSupport::TestCase
 
         Dir.chdir('foo/bar')
 
+        loader.exec_app_rails
+
         expects_exec exe
-        Rails::AppRailsLoader.exec_app_rails
 
         # Compare the realpath in case either of them has symlinks.
         #