         } else {
             controller.title = document.fileName
         }
+        
+        controller.backButton = backButton
         
         if let actionButtonImage = actionButtonImage {
             controller.actionButton = UIBarButtonItem(image: actionButtonImage, style: .plain, target: controller, action: #selector(actionButtonPressed))

    /// UIBarButtonItem used to override the default action button
    fileprivate var actionButton: UIBarButtonItem?
    
    /// Background color to apply to the collectionView.
    public var backgroundColor: UIColor? = .lightGray {
        didSet {

    /// - parameter actionStyle:       sytle of the action button
    ///
    /// - returns: a `PDFViewController`
    public class func createNew(with document: PDFDocument, title: String? = nil, actionButtonImage: UIImage? = nil, actionStyle: ActionStyle = .print, backButton: UIBarButtonItem? = nil) -> PDFViewController {
        let storyboard = UIStoryboard(name: "PDFReader", bundle: Bundle(for: PDFViewController.self))
        let controller = storyboard.instantiateInitialViewController() as! PDFViewController
        controller.document = document
