diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c
index eaff7d7393..1532392279 100644
--- a/src/common/compat_libevent.c
+++ b/src/common/compat_libevent.c
@@ -535,7 +535,7 @@ periodic_timer_new(struct event_base *base,
 #ifndef HAVE_PERIODIC
   memcpy(&timer->tv, tv, sizeof(struct timeval));
 #endif
-  event_add(timer->ev, tv);
+  event_add(timer->ev, (struct timeval *)tv); /*drop const for old libevent*/
   return timer;
 }