I get that.�� But there's lots of code out there that expects classNamed: to answer nil for names tat don't name a class.�� Why break all that code?�� If you had added checkedClassNamed: or some thing else then that old code wouldn't be broken. There needs to be some cheap way of checking whether a class with a specific name actually exists. ��classNamed: fulfilled that need.�� By redefining it you'e meant that that has to be reimplemented.�� It's not a good idea to redefine co=re behavior in this way.�� It breaks lots of code (including VMMaker).