Requirements

To qualify to become a thaumaturgist, a character must fulfill all the following criteria.

Feats: Spell Focus (conjuration).

Spells: Able to cast lesser planar ally.
Planar Ally, Lesser

Conjuration (Calling) [see text]

Level:
Clr 4
I have seen people telling wizards to become a thaumaturgist in builds, but I am curious how this could be with the pre-req being a cleric only spell. help?? is there some errata that fixes this or is it an, "Ask the DM" thing?