diff --git a/util/perl/TLSProxy/Proxy.pm b/util/perl/TLSProxy/Proxy.pm
index 38213856f51d542a4029a14abcfb386e8daecfab..a583e636cd9113d7d2d5a7a18bbda61cf459782c 100644
--- a/util/perl/TLSProxy/Proxy.pm
+++ b/util/perl/TLSProxy/Proxy.pm
@@ -44,7 +44,7 @@ BEGIN
         $s->close();
     };
     if ($@ eq "") {
-        $IP_factory = sub { IO::Socket::INET6->new(@_); };
+        $IP_factory = sub { IO::Socket::INET6->new(Domain => AF_INET6, @_); };
         $have_IPv6 = 1;
     } else {
         eval {