diff --git a/backend/notify.py b/backend/notify.py
index dea7790..8da4e77 100644
--- a/backend/notify.py
+++ b/backend/notify.py
@@ -25,7 +25,7 @@ import os
 import smtplib
 import threading
 import uuid
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from email.message import EmailMessage
 from pathlib import Path
 from typing import Any
@@ -182,7 +182,7 @@ def create_channel(name: str, channel_type: str, config: dict[str, Any]) -> dict
             "type": channel_type,
             "enabled": True,
             "config": normalized,
-            "created_at": datetime.now(timezone.utc).isoformat(),
+            "created_at": datetime.now(UTC).isoformat(),
             "last_sent_at": None,
             "last_error": None,
         }
@@ -287,7 +287,7 @@ def _send_webhook(url: str, title: str, message: str, trigger: str) -> None:
             "event": trigger,
             "title": title,
             "message": message,
-            "timestamp": datetime.now(timezone.utc).isoformat(),
+            "timestamp": datetime.now(UTC).isoformat(),
             "source": "obsigate-notify",
         },
         timeout=10.0,
@@ -345,6 +345,6 @@ def _mark_sent(channel_id: str, error: str | None) -> None:
         channels = _read_channels()
         for channel in channels:
             if channel.get("id") == channel_id:
-                channel["last_sent_at"] = datetime.now(timezone.utc).isoformat()
+                channel["last_sent_at"] = datetime.now(UTC).isoformat()
                 channel["last_error"] = error
         _write_channels(channels)