     navigationItem.rightBarButtonItem?.tintColor = navigationItem.rightBarButtonItem?.tintColor?.withAlphaComponent(alpha)
     navigationItem.leftBarButtonItems?.forEach { $0.tintColor = $0.tintColor?.withAlphaComponent(alpha) }
     navigationItem.rightBarButtonItems?.forEach { $0.tintColor = $0.tintColor?.withAlphaComponent(alpha) }
+    if #available(iOS 11.0, *) {
+      navigationItem.searchController?.searchBar.alpha = alpha
+    }
     if let titleColor = navigationBar.titleTextAttributes?[NSAttributedString.Key.foregroundColor] as? UIColor {
       navigationBar.titleTextAttributes?[NSAttributedString.Key.foregroundColor] = titleColor.withAlphaComponent(alpha)
     } else {

   - parameter scrollSpeedFactor : This factor determines the speed of the scrolling content toward the navigation bar animation
   - parameter collapseDirection : The direction of scrolling that the navigation bar should be collapsed
   - parameter additionalOffset : The additional distance that the navigation bar can move up after reaching the top of the screen. Defaults to 0
   - parameter followers: An array of `NavigationBarFollower`s that will follow the navbar. The wrapper holds the direction that the view will follow
   */
  open func followScrollView(_ scrollableView: UIView, delay: Double = 0, scrollSpeedFactor: Double = 1, collapseDirection: NavigationBarCollapseDirection = .scrollDown, additionalOffset: CGFloat = 0, followers: [NavigationBarFollower] = []) {
    savedNavBarTintColor = navigationBar.tintColor
    guard self.scrollableView == nil else {
      // Restore previous state. UIKit restores the navbar to its full height on view changes (e.g. during a modal presentation), so we need to restore the status once UIKit is done

    delayDistance = CGFloat(delay)
    scrollingEnabled = true
    self.additionalOffset = additionalOffset
    self.scrollSearchBar = scrollSearchBar
    
    // Save TabBar state (the state is changed during the transition and restored on compeltion)
    if let tab = followers.map({ $0.view }).first(where: { $0 is UITabBar }) as? UITabBar {
