diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 1b844f46b30f8ec8264480f598a9b96b26ab0dc6..762a3bd7a5aa8ea18743faceeef72a0cce6a2b81 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Require Tempfile explicitly for TestUploadedFile due to changes in class auto loading.  [Rick Olson]
+
 * Add RoutingError exception when RouteSet fails to generate a path from a Named Route. [Rick Olson]
 
 * Replace Reloadable with Reloadable::Deprecated. [Nicholas Seckar]
diff --git a/actionpack/lib/action_controller/test_process.rb b/actionpack/lib/action_controller/test_process.rb
index 2ae17c7adc0d90a1ec9cba49146aeafc9ba23a74..118e48e5cf2f54245ef0e6617de7c5e51293958b 100644
--- a/actionpack/lib/action_controller/test_process.rb
+++ b/actionpack/lib/action_controller/test_process.rb
@@ -305,6 +305,7 @@ def delete() @attributes = {} end
   #
   # Usage example, within a functional test:
   #   post :change_avatar, :avatar => ActionController::TestUploadedFile.new(Test::Unit::TestCase.fixture_path + '/files/spongebob.png', 'image/png')
+  require 'tempfile'
   class TestUploadedFile
     # The filename, *not* including the path, of the "uploaded" file
     attr_reader :original_filename