There is no good way to test this. The only thing I could think to do was to copy the new lines up above the try and run the test: $rcp = new \ReflectionProperty(parent::class, 'webDriver'); $rcp->setValue($this, null); try { parent::stop(); } catch (DriverException $e) { error_log($e->getMessage()); $rcp = new \ReflectionProperty(parent::class, 'webDriver'); $rcp->setValue($this, null); } Running the test then gives you: .............Could not connect to a Selenium 2 / WebDriver server .............Could not connect to a Selenium 2 / WebDriver server