diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 90ba8358a892b420c5bb32a48570402958a32a23..741df67a81ec85b90c780dd94ee430440c0dcb9c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -909,6 +909,9 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 	struct dst_entry *dst = &rt->dst;
 	struct fib_result res;
 
+	if (dst->dev->mtu < mtu)
+		return;
+
 	if (mtu < ip_rt_min_pmtu)
 		mtu = ip_rt_min_pmtu;