Wrong results with big_tables=1 and CTE

MariaDB [test]> SET big_tables=1;

Query OK, 0 rows affected (0.00 sec)

MariaDB [test]> with recursive qn as (select 1 as a from dual union all select a*2000 from qn where a<10000000000000000000) select * from qn;

+------+

| a    |

+------+

|    1 |

| 2000 |

+------+

2 rows in set (0.02 sec)

MariaDB [test]> SET big_tables=0;

Query OK, 0 rows affected (0.00 sec)

MariaDB [test]> with recursive qn as (select 1 as a from dual union all select a*2000 from qn where a<10000000000000000000) select * from qn;

ERROR 1690 (22003): BIGINT value is out of range in '`qn`.`a` * 2000'