diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index dae1949019d7..95703ba2c084 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -381,9 +381,8 @@ int ip6_forward(struct sk_buff *skb)
 	 *	cannot be fragmented, because there is no warranty
 	 *	that different fragments will go along one path. --ANK
 	 */
-	if (opt->ra) {
-		u8 *ptr = skb_network_header(skb) + opt->ra;
-		if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
+	if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
+		if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
 			return 0;
 	}