diff --git a/python/paddle_serving_server/web_service.py b/python/paddle_serving_server/web_service.py
index 47c39e64708d3e7871cf160efbd3982c35c71d54..d9b9e3f1b1dcfa9502096d0eab4e3be61d2bbaa6 100755
--- a/python/paddle_serving_server/web_service.py
+++ b/python/paddle_serving_server/web_service.py
@@ -88,7 +88,7 @@ class WebService(object):
             result = self.postprocess(
                 feed=request.json["feed"], fetch=fetch, fetch_map=fetch_map)
             result = {"result": result}
-        except ValueError, err:
+        except ValueError as err:
             result = {"result": err}
         return result
 
diff --git a/python/paddle_serving_server_gpu/web_service.py b/python/paddle_serving_server_gpu/web_service.py
index 886deb769d9aa7fa581cb42087c106e67c71e31b..fecc61ffa1f8637fb214cc748fb14c7ce30731ab 100644
--- a/python/paddle_serving_server_gpu/web_service.py
+++ b/python/paddle_serving_server_gpu/web_service.py
@@ -133,7 +133,7 @@ class WebService(object):
             result = self.postprocess(
                 feed=request.json["feed"], fetch=fetch, fetch_map=fetch_map)
             result = {"result": result}
-        except ValueError, err:
+        except ValueError as err:
             result = {"result": err}
         return result