diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index 2392f17040bb..2c9898469d71 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -386,7 +386,7 @@ tcp_output(struct tcpcb *tp)
 	 */
 	if (sack_rxmit == 0) {
 		if (sack_bytes_rxmt == 0)
-			len = ((int32_t)ulmin(sbavail(&so->so_snd), sendwin) -
+			len = ((int32_t)min(sbavail(&so->so_snd), sendwin) -
 			    off);
 		else {
 			int32_t cwin;