diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 22c8ea9..3dacecc 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -311,7 +311,10 @@ found:
 	else
 		fq->q.fragments = skb;
 
-	skb->dev = NULL;
+	if (skb->dev) {
+		fq->iif = skb->dev->ifindex;
+		skb->dev = NULL;
+	}
 	fq->q.stamp = skb->tstamp;
 	fq->q.meat += skb->len;
 	if (payload_len > fq->q.max_size)