Hi! There is a issue with subclasses in modules that I''m investigating on: http://dev.rubyonrails.org/ticket/2819 Basically the problem is that Object#subclasses_of intentionally skips classes in modules. I''ve wrote up a fix that also removes subclasses in modules properly: http://oaklandcutlery.com/subclasses_in_modules.diff However, the fact that the original author of Object#subclasses_of intentionally skipped classes in modules, makes me wonder if there is a specific reason for that, something I didn''t consider in my fix. Would be fantastic to hear from the author of that code.. or can you guys think of anything? Thanks! Ciao! Florian