Item_param does not preserve exact field type in EXECUTE IMMEDIATE 'CREATE TABLE AS SELECT ?' USING POINT(1,1)

DROP TABLE IF EXISTS t1;

EXECUTE IMMEDIATE 'CREATE TABLE t1 AS SELECT ?' USING POINT(1,1);

SHOW CREATE TABLE t1;

+-------+-----------------------------------------------------------------------------------------+

| Table | Create Table                                                                            |

+-------+-----------------------------------------------------------------------------------------+

| t1    | CREATE TABLE `t1` (

  `?` varbinary(25) NOT NULL

) ENGINE=InnoDB DEFAULT CHARSET=latin1 |

+-------+-----------------------------------------------------------------------------------------+

DROP TABLE IF EXISTS t1;

PREPARE stmt FROM 'CREATE OR REPLACE TABLE t1 AS SELECT ?';

EXECUTE stmt USING POINT(1,1);

SHOW CREATE TABLE t1;