diff --git a/method_executor.rb b/method_executor.rb
index b800683..f7becd0 100644
--- a/method_executor.rb
+++ b/method_executor.rb
@@ -90,7 +90,8 @@ class MethodExecutor
       while true
         sleep 0.5
         begin
-        proc_status = Process.waitpid2(pid, Process::WNOHANG)
+          SystemdNotifier.notify("WATCHDOG=1")
+          proc_status = Process.waitpid2(pid, Process::WNOHANG)
         if proc_status # 子进程已退出，返回 [pid, status]
           _, status = proc_status
           elapsed = (Time.now - tick_beg).round(2)