diff --git a/actionpack/lib/action_controller/url_rewriter.rb b/actionpack/lib/action_controller/url_rewriter.rb
index 552c2ae93e..e6d99f2eb7 100644
--- a/actionpack/lib/action_controller/url_rewriter.rb
+++ b/actionpack/lib/action_controller/url_rewriter.rb
@@ -1,3 +1,5 @@
+require 'uri'
+
 module ActionController
   # In <b>routes.rb</b> one defines URL-to-controller mappings, but the reverse
   # is also possible: an URL can be generated from one of your routing definitions.