diff --git a/sys/netinet/tcp.h b/sys/netinet/tcp.h
index 3b72094025c6..fee449f73054 100644
--- a/sys/netinet/tcp.h
+++ b/sys/netinet/tcp.h
@@ -69,7 +69,7 @@ struct tcphdr {
 #define	TH_URG	0x20
 #define	TH_ECE	0x40
 #define	TH_CWR	0x80
-#define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR)
+#define	TH_FLAGS	(TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR)
 
 	u_short	th_win;			/* window */
 	u_short	th_sum;			/* checksum */