diff --git a/scheduler_watcher.py b/scheduler_watcher.py
index 278bd1c3a..8ca4eae93 100644
--- a/scheduler_watcher.py
+++ b/scheduler_watcher.py
@@ -43,7 +43,7 @@ class SchedulerWatcher:
             if self.watcher.is_alive():
                 return
         logger.info(f"Scheduler watcher start")
-        self.watcher = threading.Thread(target=self.watcher_thread)
+        self.watcher = threading.Thread(target=self.watcher_thread, daemon=True)
         self.watcher.start()
 
     def request_extend_task_deadline(self):