T_CONCAT_EQUAL operator and object's write/read handlers

Hi! Why write_property handler is not invoked when concatenation operator is used in such case? $obj->prop .= 'a more text here'; It works fine in such example: $obj->prop = $obj->prop . 'a more text here'; In first example only read handler is invoked ,whilst read and write ones in latter. I doubt it's write handler issue. Should I have another handler like get_property_ptr_ptr_t? Piotras