Index: sys/netinet/tcp_lro.c
===================================================================
--- sys/netinet/tcp_lro.c
+++ sys/netinet/tcp_lro.c
@@ -382,7 +382,8 @@
     struct tcphdr **th)
 {
 
-	/* XXX-BZ we should check the flow-label. */
+	if (ip6->ip6_flow != mtod(m, struct ip6_hdr *)->ip6_flow)
+		return (TCP_LRO_CANNOT);
 
 	/* XXX-BZ We do not yet support ext. hdrs. */
 	if (ip6->ip6_nxt != IPPROTO_TCP)