diff --git a/tap.c b/tap.c
index e4dd804..8310891 100644
--- a/tap.c
+++ b/tap.c
@@ -899,8 +899,11 @@ static int tap_ns_tun(void *arg)
 	if (ns_enter(c) ||
 	    (tun_ns_fd = open("/dev/net/tun", flags)) < 0 ||
 	    ioctl(tun_ns_fd, TUNSETIFF, &ifr) ||
-	    !(c->pasta_ifi = if_nametoindex(c->pasta_ifn)))
+	    !(c->pasta_ifi = if_nametoindex(c->pasta_ifn))) {
+		if (tun_ns_fd != -1)
+			close(tun_ns_fd);
 		tun_ns_fd = -1;
+	}
 
 	return 0;
 }