diff --git a/backend/push.py b/backend/push.py
index 5670368..a4d2251 100644
--- a/backend/push.py
+++ b/backend/push.py
@@ -6,7 +6,7 @@ import base64
 import json
 import logging
 import os
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from pathlib import Path
 from typing import Any
 
@@ -185,7 +185,7 @@ async def subscribe_push(
         "keys": request.subscription.keys,
         "vault": request.vault,
         "username": username,
-        "created_at": datetime.now(timezone.utc).isoformat()
+        "created_at": datetime.now(UTC).isoformat()
     }
     
     _push_subscriptions.append(subscription)