public function unregisterFatalAction()
    {
        $this->fatalShouldActive = false;

        if ($this::$krexxFatal === null) {
            // There is no fatal error handler to begin with.
            return $this;
        }

        // Now we need to tell the shutdown function, that is must
        // not do anything on shutdown.
        $this::$krexxFatal->setIsActive(false);
        unregister_tick_function(array($this::$krexxFatal, 'tickCallback'));
        return $this;
    }