diff --git a/kernel/watchdog_perf.c b/kernel/watchdog_perf.c
index 2fdb96eaf493..a78ff092d636 100644
--- a/kernel/watchdog_perf.c
+++ b/kernel/watchdog_perf.c
@@ -144,6 +144,7 @@ static int hardlockup_detector_event_create(void)
 			 PTR_ERR(evt));
 		return PTR_ERR(evt);
 	}
+	WARN_ONCE(this_cpu_read(watchdog_ev), "unexpected watchdog_ev leak");
 	this_cpu_write(watchdog_ev, evt);
 	return 0;
 }