diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 7d339fc1057f..150b4923fb72 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1361,7 +1361,7 @@ static int __ip6_append_data(struct sock *sk,
 	 */
 
 	cork->length += length;
-	if (((length > mtu) ||
+	if ((((length + fragheaderlen) > mtu) ||
 	     (skb && skb_is_gso(skb))) &&
 	    (sk->sk_protocol == IPPROTO_UDP) &&
 	    (rt->dst.dev->features & NETIF_F_UFO) &&