diff --git a/websocket_server/events/messages.py b/websocket_server/events/messages.py
index 0279d0d..d7eab1b 100644
--- a/websocket_server/events/messages.py
+++ b/websocket_server/events/messages.py
@@ -42,6 +42,12 @@ def register_socketio_handlers(socketio):
             if worker_id:
                 del connected_workers[worker_id]
                 logger.warning(f"Worker {worker_id} disconnected")
+
+                # Delete Redis ping keys to prevent stale heartbeats from marking worker online
+                redis_client = get_redis_client()
+                redis_client.delete(f"ws_liveness:{worker_id}")
+                redis_client.delete(f"ws_latency:{worker_id}")
+
                 notify_worker_disconnect(worker_id)