The Symfony API documentation for HttpFoundation is missing RedisSessionHandler class in 4.1, link: https://api.symfony.com/4.1/Symfony/Component/HttpFoundation/Session/Storage/Handler/RedisSessionHandler.html The class is in 4.1, github link: https://github.com/symfony/http-foundation/blob/4.1/Session/Storage/Handler/RedisSessionHandler.php The documentation links to 404 page for RedisSessionHandler from https://symfony.com/doc/current/components/http_foundation/session_configuration.html#custom-save-handlers