2 files changed, 4 insertions, 2 deletions

diff --git a/sys/netinet/tcp.h b/sys/netinet/tcp.h
index e0133a752078..0ba98b448d96 100644
--- a/sys/netinet/tcp.h
+++ b/sys/netinet/tcp.h
@@ -78,6 +78,8 @@ struct tcphdr {
 
 #define	TCPOPT_EOL		0
 #define	   TCPOLEN_EOL			1
+#define	TCPOPT_PAD		0		/* padding after EOL */
+#define	   TCPOLEN_PAD			1
 #define	TCPOPT_NOP		1
 #define	   TCPOLEN_NOP			1
 #define	TCPOPT_MAXSEG		2
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index 44adab6e3857..f94b8541b224 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -1395,8 +1395,8 @@ tcp_addoptions(struct tcpopt *to, u_char *optp)
 	 * people with padding of EOLs.
 	 */
 	while (optlen % 4) {
-		optlen += 1;
-		*optp++ = 0x00;
+		optlen += TCPOLEN_PAD;
+		*optp++ = TCPOPT_PAD;
 	}
 
 	KASSERT(optlen <= TCP_MAXOLEN, ("%s: TCP options too long", __func__));