Prompt for LUKS passphrase during Kickstart on RHEL 7.4

I've read some documentation (from RHEL 6 and 7) that seems to indicate one can omit the --passphrase option on a part line like:

part pv.sata --fstype="lvmpv" --size=304220 --ondisk=sda --encrypted

My understanding was this would cause Anaconda to prompt for an encryption passphrase during a Kickstart-automated install, removing the need to include a plaintext passphrase in the Kickstart file.

I've tried omitting --passphrase entirely and including it but leaving it empty and in both cases Anaconda failed because the passphrase was not provided. Is there some way to get the desired behaviour in RHEL 7.4?