diff --git a/include/net/ip.h b/include/net/ip.h
index 37165fb..08f36cd 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -313,10 +313,9 @@
 	return min(dst->dev->mtu, IP_MAX_MTU);
 }
 
-static inline unsigned int ip_skb_dst_mtu(const struct sk_buff *skb)
+static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
+					  const struct sk_buff *skb)
 {
-	struct sock *sk = skb->sk;
-
 	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
 		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;