diff --git a/usr.bin/csup/auth.c b/usr.bin/csup/auth.c
index c90d71930fd..1704eba53b2 100644
--- a/usr.bin/csup/auth.c
+++ b/usr.bin/csup/auth.c
@@ -293,7 +293,7 @@ auth_makechallenge(struct config *config, char *challenge)
 	gettimeofday(&tv, NULL);
 	pid = getpid();
 	ppid = getppid();
-	srand(tv.tv_usec ^ tv.tv_sec ^ pid);
+	srandom(tv.tv_usec ^ tv.tv_sec ^ pid);
 	addrlen = sizeof(laddr);
 	error = getsockname(config->socket, (struct sockaddr *)&laddr, &addrlen);
 	if (error < 0) {