SQL_CALC_FOUND_ROWS yields wrong result

CREATE TEMPORARY TABLE A(`id` mediumint, `value` mediumint, PRIMARY KEY(`id`,`value`));

INSERT INTO A VALUES (1,1),(2,2),(3,3);

CREATE TEMPORARY TABLE B(`id` mediumint, PRIMARY KEY(`id`));

INSERT INTO B VALUES (1),(2),(3);

SELECT SQL_CALC_FOUND_ROWS 1 FROM A LEFT JOIN B ON A.`id` = B.`id` WHERE B.`id` IS NULL ORDER BY `value` DESC;

SELECT FOUND_ROWS() AS `count`;

SELECT COUNT(*) FROM (SELECT 1 FROM A LEFT JOIN B ON A.`id` = B.`id` WHERE B.`id` IS NULL ORDER BY `value` DESC) AS `x`;