diff --git a/miniupnpd/upnppinhole.c b/miniupnpd/upnppinhole.c
index ac9aa88..08f1cf6 100644
--- a/miniupnpd/upnppinhole.c
+++ b/miniupnpd/upnppinhole.c
@@ -131,7 +131,7 @@ upnp_add_inboundpinhole(const char * raddr,
 #if defined(USE_PF) || defined(USE_NETFILTER)
 	*uid = add_pinhole (0/*ext_if_name*/, raddr, rport,
 	                    iaddr, iport, proto, desc, timestamp);
-	return 1;
+	return *uid >= 0 ? 1 : -1;
 #else
 	return -42;	/* not implemented */
 #endif