diff --git a/usr.sbin/tcpsso/tcpsso.c b/usr.sbin/tcpsso/tcpsso.c
--- a/usr.sbin/tcpsso/tcpsso.c
+++ b/usr.sbin/tcpsso/tcpsso.c
@@ -192,6 +192,7 @@
 	tcp_entry(TCP_REMOTE_UDP_ENCAPS_PORT),	/* int */
 	tcp_entry(TCP_MAXSEG),			/* int */
 	tcp_entry(TCP_TXTLS_MODE),		/* unsigned int */
+	tcp_entry(TCP_MAXUNACKTIME),		/* unsigned int */
 	tcp_entry(TCP_KEEPIDLE),		/* unsigned int */
 	tcp_entry(TCP_KEEPINTVL),		/* unsigned int */
 	tcp_entry(TCP_KEEPINIT),		/* unsigned int */