diff --git a/apitools/base/py/encoding_test.py b/apitools/base/py/encoding_test.py
index 182d4551..6120c4bf 100644
--- a/apitools/base/py/encoding_test.py
+++ b/apitools/base/py/encoding_test.py
@@ -331,7 +331,7 @@ def testInvalidEnumEncodingInAMap(self):
             json_msg)
         new_msg = encoding.MessageToJson(msg)
         self.assertEqual('{"key_one": {"field_one": "BAD_VALUE"}}',
-                         encoding.MessageToJson(msg))
+                         new_msg)
 
     def testIncludeFields(self):
         msg = SimpleMessage()