Tests: run proxy.t ipv6 test on mainline built without --with-ipv6.
diff --git a/proxy.t b/proxy.t
index 18542d9..0ee7c29 100644
--- a/proxy.t
+++ b/proxy.t
@@ -81,7 +81,7 @@
 like(http_get('/var?b=u/'), qr/SEE-THIS/, 'proxy with variables to upstream');
 
 SKIP: {
-skip 'no ipv6', 1 unless $t->has_module('ipv6')
+skip 'no ipv6', 1 unless $t->has_module('ipv6') or $t->has_feature('ipv6')
 	and socket(my $s, &AF_INET6, &SOCK_STREAM, 0);
 
 TODO: {