dnscache does not forward NXDOMAIN TTLs

[ksool]

I'm in the process of switching from BIND to dnscache and have hit a snag. I setup a forwarding cache that I will run on my home network. I use forwarding because I have an openvpn client that runs it own local dnscache. So far, I've got it working just fine for caching responses but I cannot get the vpn client to cache NXDOMAIN responses, that is, to cache a "no such domain" response. I am under the impression that this is because the dnscache server doesn't forward SOA records which would contain the NXDOMAIN TTL.

Is it possible to get this dnscache to forward the full record it receives (or at least to include the SOA record)?