diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 6cee844..f639866 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1296,7 +1296,7 @@
 {
 	u8 proto;
 
-	if (!data)
+	if (!data || !data[IFLA_IPTUN_PROTO])
 		return 0;
 
 	proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);