diff --git a/app/main.py b/app/main.py
index 20c399f..b13ac9a 100644
--- a/app/main.py
+++ b/app/main.py
@@ -115,7 +115,7 @@ config = Config()
 
 class ObjectSerializer(json.JSONEncoder):
     def default(self, obj):
-        if isinstance(obj, object):
+        if hasattr(obj, '__dict__'):
             return obj.__dict__
         else:
             return json.JSONEncoder.default(self, obj)