diff --git a/test/integration/action_controller/serialization_test.rb b/test/integration/action_controller/serialization_test.rb
index 7ffd4c56..9e05e904 100644
--- a/test/integration/action_controller/serialization_test.rb
+++ b/test/integration/action_controller/serialization_test.rb
@@ -1,4 +1,5 @@
 require 'test_helper'
+require 'json'
 
 module ActionController
   module Serialization