IPv6 resolvers seems not works (no replies)

Hello,
I'm trying to add IPv6 address as a nameserver to able resolve addresses in
IPv6-only environment:

resolvers google_dns_10m
nameserver google_dns1 2001:4860:4860::8888:53
nameserver google_dns2 2001:4860:4860::8844:53
hold valid 10m
resolve_retries 2

But I getting error:
[ALERT] 099/133733 (10412) : Starting [google_dns_10m/google_dns1]
nameserver: can't connect socket.

As I understood resolver uses AF_INET when connecting to the nameserver and
that's why IPv6 doesn't work.
Is it possible to add IPv6 support for resolvers?

Thanks.