LDAP Provisioner does not provision voPosixAccount objectClass

Running commit 7ac971 I have the LDAP Provisioner configured to provision both posixAccount and voPosixAccount. The CoPerson record has a single UnixCluster. It has Active status with a Username, Uder ID (UID) Number, GECOS, Login Shell, Home Directory, and Primary Group (a unixCluster Group, automatically generated). 

The posixAccount objectClass is being correctly provisioned but the voPosixAccount objectClass is not being provisioned.

Note that the OpenLDAP slapd does have the voPosixAccount and voPosixGroup schema defined.