diff --git a/actionpack/test/controller/render_test.rb b/actionpack/test/controller/render_test.rb
index bf72730bea9b1..af7236ed26658 100644
--- a/actionpack/test/controller/render_test.rb
+++ b/actionpack/test/controller/render_test.rb
@@ -1,5 +1,6 @@
 require 'abstract_unit'
 require 'controller/fake_models'
+require 'pathname'
 
 module Fun
   class GamesController < ActionController::Base