IS JSON prediction does not work on generated columns

MariaDB [test]> CREATE OR REPLACE TABLE t (j JSON, jj BOOL GENERATED ALWAYS AS (j IS JSON ARRAY) VIRTUAL);

ERROR 1305 (42000): FUNCTION test.is_json does not exist

MariaDB [test]> CREATE OR REPLACE TABLE t (j JSON CHECK (j IS JSON ARRAY));

ERROR 1305 (42000): FUNCTION test.is_json does not exist

MariaDB [test]> CREATE OR REPLACE TABLE t (j JSON CHECK (j IS NOT JSON));

ERROR 1305 (42000): FUNCTION test.is_json does not exist

MariaDB [test]> CREATE OR REPLACE TABLE t (j JSON, jj BOOL DEFAULT (j IS NOT JSON ARRAY));

ERROR 1305 (42000): FUNCTION test.is_json does not exist