diff --git a/sys/kern/sched_ule.c b/sys/kern/sched_ule.c
index 1fe3795..8a4ddea 100644
--- a/sys/kern/sched_ule.c
+++ b/sys/kern/sched_ule.c
@@ -838,6 +838,7 @@ sched_balance(void)
 		return;
 	tdq = TDQ_SELF();
 	TDQ_UNLOCK(tdq);
+	CRITICAL_ASSERT(curthread);
 	sched_balance_group(cpu_top);
 	TDQ_LOCK(tdq);
 }