(See http://bugs.python.org/issue16251) The pickle module looks up special methods on instances rather than using the behavior described in the language reference (or even just looking them up on the class). This means that custom __getattribute__() and __getattr__() implementations may get triggered (e.g. if there is no __reduce__() implemented). Bringing pickle in sync with the language reference would not involve a big change, but it would impact anyone that relies on the current behavior. Most notably, proxy types could exist which leverage the current semantics. I look at this as trading one "bug" for another in a . So I want to get some general feedback on the situation and see what others consider to be the trade-offs of fixing or not fixing this bug. I'm particularly interested in existing cases where code uses the current behavior. With that in hand we could assess what alternatives exist in those cases or how we could better document workarounds for the current behavior. -eric