--TEST-- __sleep() returning undefined declared properties --FILE-- pub, $this->prot, $this->priv); } public function __sleep() { return ['pub', 'prot', 'priv']; } } var_dump(serialize(new Test)); ?> --EXPECTF-- Warning: serialize(): "pub" returned as member variable from __sleep() but does not exist in %s on line %d Warning: serialize(): "prot" returned as member variable from __sleep() but does not exist in %s on line %d Warning: serialize(): "priv" returned as member variable from __sleep() but does not exist in %s on line %d string(15) "O:4:"Test":0:{}"