diff --git a/sched/wdog/wd_start.c b/sched/wdog/wd_start.c
index 20098630ace..a8d2b01f451 100644
--- a/sched/wdog/wd_start.c
+++ b/sched/wdog/wd_start.c
@@ -386,7 +386,7 @@ int wd_start(FAR struct wdog_s *wdog, clock_t delay,
 {
   /* Ensure delay is within the range the wdog can handle. */
 
-  if (delay > WDOG_MAX_DELAY)
+  if (delay >= WDOG_MAX_DELAY)
     {
       return -EINVAL;
     }