diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c
index 7a3f89ed37..789a8c7df4 100644
--- a/src/libsystemd/sd-event/sd-event.c
+++ b/src/libsystemd/sd-event/sd-event.c
@@ -3725,7 +3725,7 @@ _public_ int sd_event_run(sd_event *e, uint64_t timeout) {
                 this_run = now(CLOCK_MONOTONIC);
 
                 l = u64log2(this_run - e->last_run);
-                assert(l < sizeof(e->delays));
+                assert(l < ELEMENTSOF(e->delays));
                 e->delays[l]++;
 
                 if (this_run - e->last_log >= 5*USEC_PER_SEC) {