diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c
index 98c90c561d13..e5f7dde531ca 100644
--- a/sys/netinet/tcp_syncache.c
+++ b/sys/netinet/tcp_syncache.c
@@ -1668,7 +1668,8 @@ syncache_add(struct in_conninfo *inc, struct tcpopt *to, struct tcphdr *th,
 		sc->sc_peer_mss = to->to_mss;	/* peer mss may be zero */
 	if (ltflags & TF_NOOPT)
 		sc->sc_flags |= SCF_NOOPT;
-	if ((th->th_flags & (TH_ECE|TH_CWR)) && V_tcp_do_ecn)
+	if (((th->th_flags & (TH_ECE|TH_CWR)) == (TH_ECE|TH_CWR)) &&
+	    V_tcp_do_ecn)
 		sc->sc_flags |= SCF_ECN;
 
 	if (V_tcp_syncookies)