diff --git a/actionpack/lib/action_dispatch/testing/test_process.rb b/actionpack/lib/action_dispatch/testing/test_process.rb
index d430691429..397bda41d5 100644
--- a/actionpack/lib/action_dispatch/testing/test_process.rb
+++ b/actionpack/lib/action_dispatch/testing/test_process.rb
@@ -29,7 +29,7 @@ module ActionDispatch
       @response.redirect_url
     end
 
-    # Shortcut for <tt>ARack::Test::UploadedFile.new(ActionController::TestCase.fixture_path + path, type)</tt>:
+    # Shortcut for <tt>Rack::Test::UploadedFile.new(ActionController::TestCase.fixture_path + path, type)</tt>:
     #
     #   post :change_avatar, :avatar => fixture_file_upload('/files/spongebob.png', 'image/png')
     #