stack level too deep (when changing model inheritance)

Question

I'm trying to use the citier gem to convert some models that already exist in the following way. So far this works:

Created models:

Attachable < ActiveRecord::Base
Link < Attachable

I added acts_as_citier to both models, created and ran the migrations with no problem. Database views are created as well. Now if I try to do this to an existing model:

Before:

SpecialLink < ActiveRecord::Base

After:

SpecialLink < Link

and then I try to run any command like rails g migration or rails console, I get:

script/rails:6: stack level too deep (SystemStackError)

Unfortunately, this doesn't tell me a whole lot beyond a suspicion that I have an infinite loop somewhere. Does anyone know what might be causing this? Or have an idea of where I can look or get more information about the issue? It would not be a good solution for me to have to create the models again from scratch to work with citier...