diff --git a/event.c b/event.c
index f2f9e83c..2a2150ac 100644
--- a/event.c
+++ b/event.c
@@ -433,6 +433,7 @@ event_once(int fd, short events,
 		event_set(&eonce->ev, fd, events, event_once_cb, eonce);
 	} else {
 		/* Bad event combination */
+		free(eonce);
 		return (-1);
 	}