diff --git a/backend/app/routers/connections.py b/backend/app/routers/connections.py
index bfd4f9a..26b72bd 100644
--- a/backend/app/routers/connections.py
+++ b/backend/app/routers/connections.py
@@ -589,7 +589,7 @@ async def cancel_request(
     # Silent cleanup: remove the notification sent to the receiver
     await db.execute(
         delete(Notification).where(
-            Notification.source_type == "connection_request",
+            Notification.source_type == NOTIF_TYPE_CONNECTION_REQUEST,
             Notification.source_id == request_id,
             Notification.user_id == receiver_id,
         )