diff --git a/usr.sbin/rpc.lockd/lock_proc.c b/usr.sbin/rpc.lockd/lock_proc.c
index c526be188f1..221ee47adf0 100644
--- a/usr.sbin/rpc.lockd/lock_proc.c
+++ b/usr.sbin/rpc.lockd/lock_proc.c
@@ -48,6 +48,7 @@ __RCSID("$NetBSD: lock_proc.c,v 1.7 2000/10/11 20:23:56 is Exp $");
 #include <stdio.h>
 #include <string.h>
 #include <syslog.h>
+#include <unistd.h>
 #include <netconfig.h>
 
 #include <rpc/rpc.h>