CentOS 4.5 to 5, Dovecot and auth_userdb/auth_passdb

I've been using IMAP for my mail, by way of Dovecot. With my recent upgrade to CentOS 5, Dovecot stopped working. Naturally, it fell to me to discover why. The problem was actually quite simple - the auth_userdb and auth_passdb declarations had been deprecated.

So, on CentOS 4.5, I had:

auth_userdb = passwd-file userdb
auth_passdb = passwd-file passdb

Dovecot on CentOS 5 required:

userdb passwd-file {
args = userdb
}
passdb passwd-file {
args = passdb
}