diff --git a/actionpack/test/ts_isolated.rb b/actionpack/test/ts_isolated.rb
index 0670e0100b..cb775508ff 100644
--- a/actionpack/test/ts_isolated.rb
+++ b/actionpack/test/ts_isolated.rb
@@ -1,3 +1,4 @@
+$:.unshift(File.dirname(__FILE__))
 $:.unshift(File.dirname(__FILE__) + '/../../activesupport/lib')
 
 require 'test/unit'