--TEST-- MongoDB\BSON\ObjectId serialization --FILE-- <?php var_dump($oid = new MongoDB\BSON\ObjectId('576c25db6118fd406e6e6471')); var_dump($s = serialize($oid)); var_dump(unserialize($s)); ?> ===DONE=== <?php exit(0); ?> --EXPECTF-- object(MongoDB\BSON\ObjectId)#%d (%d) { ["oid"]=> string(24) "576c25db6118fd406e6e6471" } string(82) "C:21:"MongoDB\BSON\ObjectId":48:{a:1:{s:3:"oid";s:24:"576c25db6118fd406e6e6471";}}" object(MongoDB\BSON\ObjectId)#%d (%d) { ["oid"]=> string(24) "576c25db6118fd406e6e6471" } ===DONE===