diff --git a/sched/sig_timedwait.c b/sched/sig_timedwait.c
index f71e65961a..3091ee384d 100644
--- a/sched/sig_timedwait.c
+++ b/sched/sig_timedwait.c
@@ -260,6 +260,8 @@ int sigtimedwait(FAR const sigset_t *set, FAR struct siginfo *info,
           /* Create a watchdog */
 
           rtcb->waitdog = wd_create();
+          DEBUGASSERT(rtcb->waitdog);
+
           if (rtcb->waitdog)
             {
               /* This little bit of nonsense is necessary for some