unknown keyword 'dns64-prefix'

[Jason Bailey]

I'm trying to set up DNS64 on a CentOS 7 box but unbound-checkconf 
complaining about the DNS64 configuration directives.

These are the errors I'm getting:
unbound-checkconf: /etc/unbound/unbound.conf:499:error: unknown keyword 
'dns64-prefix'
unbound-checkconf: /etc/unbound/unbound.conf:499: error: stray ':'
unbound-checkconf: /etc/unbound/unbound.conf:499: error: unknown keyword 
'64'
unbound-checkconf: /etc/unbound/unbound.conf:499: error: stray ':'
unbound-checkconf: /etc/unbound/unbound.conf:499: error: unknown keyword 
'ff9b'
unbound-checkconf: /etc/unbound/unbound.conf:499: error: stray ':'
unbound-checkconf: /etc/unbound/unbound.conf:499: error: stray ':'
unbound-checkconf: /etc/unbound/unbound.conf:499: error: unknown keyword 
'0/96'

I'm using configs based on a working unbound installation on CentOS 6 
that was successfully doing DNS64, so I'm fairly certain it isn't a 
syntax issue. Does the CentOS unbound package not include the dns64 
module?? How would I check?

Jason