diff --git a/sys/net/route.c b/sys/net/route.c
index e8a7e9a499f1..957c54793368 100644
--- a/sys/net/route.c
+++ b/sys/net/route.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: route.c,v 1.205 2018/01/23 07:20:10 ozaki-r Exp $	*/
+/*	$NetBSD: route.c,v 1.206 2018/01/30 11:01:04 ozaki-r Exp $	*/
 
 /*-
  * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
@@ -97,7 +97,7 @@
 #endif
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.205 2018/01/23 07:20:10 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.206 2018/01/30 11:01:04 ozaki-r Exp $");
 
 #include <sys/param.h>
 #ifdef RTFLUSH_DEBUG
@@ -256,6 +256,7 @@ static struct {
 	struct work		wk;
 	kmutex_t		lock;
 	SLIST_HEAD(, rtentry)	queue;
+	bool			enqueued;
 } rt_free_global __cacheline_aligned;
 
 /* psref for rtentry */
@@ -459,6 +460,7 @@ rt_init(void)
 
 	mutex_init(&rt_free_global.lock, MUTEX_DEFAULT, IPL_SOFTNET);
 	SLIST_INIT(&rt_free_global.queue);
+	rt_free_global.enqueued = false;
 
 	rt_psref_class = psref_class_create("rtentry", IPL_SOFTNET);
 
@@ -693,6 +695,7 @@ rt_free_work(struct work *wk, void *arg)
 		struct rtentry *rt;
 
 		mutex_enter(&rt_free_global.lock);
+		rt_free_global.enqueued = false;
 		if ((rt = SLIST_FIRST(&rt_free_global.queue)) == NULL) {
 			mutex_exit(&rt_free_global.lock);
 			return;
@@ -718,8 +721,11 @@ rt_free(struct rtentry *rt)
 	mutex_enter(&rt_free_global.lock);
 	rt_ref(rt);
 	SLIST_INSERT_HEAD(&rt_free_global.queue, rt, rt_free);
+	if (!rt_free_global.enqueued) {
+		workqueue_enqueue(rt_free_global.wq, &rt_free_global.wk, NULL);
+		rt_free_global.enqueued = true;
+	}
 	mutex_exit(&rt_free_global.lock);
-	workqueue_enqueue(rt_free_global.wq, &rt_free_global.wk, NULL);
 }
 
 #ifdef NET_MPSAFE