diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 625a38ccb5d94..0bf09a9bca4e0 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -265,7 +265,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 
 static inline unsigned int ip6_skb_dst_mtu(struct sk_buff *skb)
 {
-	int mtu;
+	unsigned int mtu;
 
 	struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
 				inet6_sk(skb->sk) : NULL;