diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 548d575..0433466 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3286,7 +3286,7 @@
 		 * connection startup slow start one packet too
 		 * quickly.  This is severely frowned upon behavior.
 		 */
-		if (!(scb->flags & TCPCB_FLAG_SYN)) {
+		if (!(scb->flags & TCPHDR_SYN)) {
 			flag |= FLAG_DATA_ACKED;
 		} else {
 			flag |= FLAG_SYN_ACKED;