diff --git a/python/paddle/fluid/tests/unittests/dist_transformer.py b/python/paddle/fluid/tests/unittests/dist_transformer.py
index 5d6b1ba07911f9774438504f8485ecafac255839..ee8020a73546cb9037e9dc4be589c62bb1b6b937 100644
--- a/python/paddle/fluid/tests/unittests/dist_transformer.py
+++ b/python/paddle/fluid/tests/unittests/dist_transformer.py
@@ -172,7 +172,7 @@ def get_transpiler(trainer_id, main_program, pserver_endpoints, trainers):
     return t
 
 
-class DistTransformer2x2:
+class DistTransformer2x2(object):
     def run_pserver(self, pserver_endpoints, trainers, current_endpoint,
                     trainer_id):
         get_model()