Finders don't automatically convert string uuid's into Cql::Uuid before execute

Executing a finder like this:
State.find_by_dot_id_and_namespace_and_type_and_id('fef87e70-d405-11e3-9363-31301ac5f848', 'dev', 'object', 'alarm/test_state_id')

Gives me the error:
ql::QueryError: Invalid STRING constant (fef87e70-d405-11e3-9363-31301ac5f848) for dot_id of type uuid

dot_id is a uuid primary key colum and should have been automatically serialized.