diff --git a/bot/src/bot_graphql/queries/user_query.py b/bot/src/bot_graphql/queries/user_query.py
index ceeab6d4..a6cffa64 100644
--- a/bot/src/bot_graphql/queries/user_query.py
+++ b/bot/src/bot_graphql/queries/user_query.py
@@ -56,7 +56,7 @@ class UserQuery(DataQueryWithHistoryABC):
         self.set_field("xp", self.resolve_xp)
         self.set_field("messageCount", lambda x, *_: x.message_count)
         self.set_field("reactionCount", lambda x, *_: x.reaction_count)
-        self.set_field("birthday", lambda x, *_: x.birthday)
+        self.set_field("birthday", lambda x, *_: None if x.birthday is None else x.birthday.strftime("%d.%m.%Y"))
         self.set_field("ontime", self.resolve_ontime)
         self.set_field("level", self.resolve_level)
         self.add_collection(