how to use the popToViewController

I'm trying to navigate to another ViewController but it's not connected by segue, so I programmed the nav bar and what I want it's when y push the button named "Start Over" the ViewController that I'm requesting appears, but this errors appears: "Cannot convert value of type MemeEditorViewController.Type yo expected argument type UIViewController" So I don't how to deal with. Here's my code, maybe you could help me better. override func viewDidLoad() { super.viewDidLoad() self.navigationItem.rightBarButtonItem = UIBarButtonItem(title:"Start Over", style: .Plain, target: self, action: "startOver") } func startOver(){ if let navigationController = self.navigationController { navigationController.popToViewController(MemeEditorViewController, animated: true) } } }