I really struggled with this part, the easiest way I found was to copy the original code from [active_support/core_ext/class/attribute_accessors.rb](https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/class/attribute_accessors.rb) and do what they did. I will try to put it in the configurable module where it belongs. I couldn't get it working there yesterday but I might have been doing something wrong :)