On mongoid 3 master

Assuming I have a collection that has this document:

{ "_id" : ObjectId("4eccf9abaa673bf4c07ef0e1"), "id" : "69199", "some_field" : "80570", "name" : "Shaw Direct SNCAN"}

Querying using where(id: '69199') or where('id'=>'69199') now preforms the query on the _id field:

MOPED: localhost:27017 QUERY database=main collection=sources selector=

{"_id"=>"69199"}

flags=[:slave_ok] limit=-1 skip=0 fields=nil (0.0ms)

Unfortunately this is an external DB and I have no way to change the column name.
It used to work fine before Moped. Is there anyway to force the query to search on id instead of on _id ?