I might be mistaken, but I think there's a bug in: http://twistedmatrix.com/projects/core/documentation/howto/options.html In the section "Inheritance, Or: How I Learned to Stop Worrying and Love the Superclass", it shows two classes, one which inherits from the other. It then shows the same thing, but as a single class. In the single class example, I think the base class should be usage.Options, not BaseOptions. I'll open a ticket if this is a bug, otherwise sorry for wasting your time.