Can't bind to link-local IPv6 address

ports:
  dns:
    - [fe80::31b5:c6fa:aad2:5ef1%eth0]:53

I'm trying to get Blocky to listen on the link-local IPv6 address of my eth0 interface. Since link-local addresses aren't unique, the scope id (%eth0) has be passed, too.

This works for other services, but Blocky doesn't start because:

* freebind udp listener on [fe80::31b5:c6fa:aad2:5ef1%eth0]:53 failed: listen udp [fe80::31b5:c6fa:aad2:5ef1>
* tcp listener on [fe80::31b5:c6fa:aad2:5ef1%eth0]:53 failed: listen tcp [fe80::31b5:c6fa:aad2:5ef1%eth0]:53>

(Not using freeBind doesn't help)

I tried other variations of specifying the scope it, but it looks like there is no way to get this to work?