diff --git a/vl.c b/vl.c
index 70950f8..7552fde 100644
--- a/vl.c
+++ b/vl.c
@@ -1041,6 +1041,10 @@ void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
     ts->expire_time = expire_time;
     ts->next = *pt;
     *pt = ts;
+
+    /* rearm if the necessary */
+    if (pt == &active_timers[ts->clock->type])
+        qemu_rearm_alarm_timer(alarm_timer);
 }
 
 int qemu_timer_pending(QEMUTimer *ts)