When foreign code uses ref() on a proxy object, it sees the proxy object's class, not the class that the object is proxying for. The proxy object would need the foriegn code to be told that the proxy object is of the proxied class. That is, ref( $obj ) or its equivalent that I'm inquiring about would not return $obj's class but the class that $obj is proxying for. This looks like the same problem that UNIVERSAL::isa and UNIVERSAL::isa were created for.