diff --git a/src/i_tcp.c b/src/i_tcp.c
index ca55515ab293b78e8b2bac7c123ca2a7889aa530..7878d1fbbb6c9313d2ce2b9c38460effe7ca2a28 100644
--- a/src/i_tcp.c
+++ b/src/i_tcp.c
@@ -857,7 +857,7 @@ static boolean UDP_Socket(void)
 	struct my_addrinfo *ai, *runp, hints;
 	int gaie;
 #ifdef HAVE_IPV6
-	const INT32 b_ipv6 = M_CheckParm("-ipv6");
+	const INT32 b_ipv6 = !M_CheckParm("-noipv6");
 #endif
 	const char *serv;