diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 51424df..c146a02 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1564,7 +1564,7 @@
 		return 0;
 	}
 
-	if (skb->len < (skb->h.th->doff << 2) || tcp_checksum_complete(skb))
+	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
 		goto csum_err;
 
 	if (sk->sk_state == TCP_LISTEN) {