As per: https://www.php.net/manual/en/ui.installation.php So the version information shouldn't give the impression that the classes/methods are available in PHP itself. They are only available in the PECL extension. Patch provided by jrfnl. git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@349877 c90b9560-bf6c-de11-be94-00142212c4b1