diff --git a/web/paperclip_api.py b/web/paperclip_api.py
index 10567a2..ae244df 100644
--- a/web/paperclip_api.py
+++ b/web/paperclip_api.py
@@ -19,7 +19,7 @@ from __future__ import annotations
 
 import logging
 import os
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import Any
 
 import httpx
@@ -104,7 +104,7 @@ async def emit_case_status_webhook(
                 "oldStatus": old_status,
                 "newStatus": new_status,
                 "companyId": company_id,
-                "timestamp": datetime.utcnow().isoformat() + "Z",
+                "timestamp": datetime.now(timezone.utc).isoformat(),
             },
             run_id=run_id,
             timeout=5.0,