diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 9b21d67..c2e629d 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -536,8 +536,8 @@
 				   &fl->fl6_dst,
 				   total_len, fl->proto, tmp_csum);
 
-	if (tmp_csum == 0 && fl->proto == IPPROTO_UDP)
-		tmp_csum = -1;
+	if (csum == 0 && fl->proto == IPPROTO_UDP)
+		csum = CSUM_MANGLED_0;
 
 	if (skb_store_bits(skb, offset, &csum, 2))
 		BUG();