diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 4cc12eeca7ab..0db120d2a4fe 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1439,10 +1439,13 @@ EXPORT_SYMBOL_GPL(ip6_update_pmtu);
 
 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
 {
+	int oif = sk->sk_bound_dev_if;
 	struct dst_entry *dst;
 
-	ip6_update_pmtu(skb, sock_net(sk), mtu,
-			sk->sk_bound_dev_if, sk->sk_mark);
+	if (!oif && skb->dev)
+		oif = l3mdev_master_ifindex(skb->dev);
+
+	ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark);
 
 	dst = __sk_dst_get(sk);
 	if (!dst || !dst->obsolete ||