diff --git a/frontend/src/plugins/httputil.ts b/frontend/src/plugins/httputil.ts
index 9aa7ca9..6c5218d 100644
--- a/frontend/src/plugins/httputil.ts
+++ b/frontend/src/plugins/httputil.ts
@@ -57,7 +57,7 @@ function _respToMsg(resp: any): Msg {
 }
 
 function isMsg(obj: any): obj is Msg {
-  return 'success' in obj && 'msg' in obj && 'obj' in obj
+  return Object.hasOwn(obj,'success') && Object.hasOwn(obj,'msg') && Object.hasOwn(obj, 'obj')
 }
   
 const HttpUtils = {