diff --git a/src/timers.c b/src/timers.c
index 7db0cc2..ed399dc 100644
--- a/src/timers.c
+++ b/src/timers.c
@@ -57,7 +57,6 @@ void uc_timers_add(struct UCTimers *timers, struct UCTimer *timer, int sec, int
 
     assert(timer->callback != NULL);
     if (timer->callback == NULL) { //must be set. 
-        assert(timer->callback != NULL);
         return;
     }