diff --git a/actionpack/lib/action_controller.rb b/actionpack/lib/action_controller.rb
index e94d49269770..a59dd76a3750 100644
--- a/actionpack/lib/action_controller.rb
+++ b/actionpack/lib/action_controller.rb
@@ -33,6 +33,7 @@
 
 gem 'rack', '~> 1.0.0'
 require 'rack'
+require 'action_controller/cgi_ext'
 
 module ActionController
   # TODO: Review explicit to see if they will automatically be handled by