diff --git a/DGElasticPullToRefresh/DGElasticPullToRefreshExtensions.swift b/DGElasticPullToRefresh/DGElasticPullToRefreshExtensions.swift
index cf71bff..774aa5a 100644
--- a/DGElasticPullToRefresh/DGElasticPullToRefreshExtensions.swift
+++ b/DGElasticPullToRefresh/DGElasticPullToRefreshExtensions.swift
@@ -183,8 +183,8 @@ public extension UIPanGestureRecognizer {
 // MARK: -
 // MARK: (UIGestureRecognizerState) Extension
 
-public extension UIGestureRecognizerState {
-    func dg_isAnyOf(values: [UIGestureRecognizerState]) -> Bool {
-        return values.contains({ $0 == self })
+public extension UIGestureRecognizer.State {
+    func dg_isAnyOf(_ values: [UIGestureRecognizer.State]) -> Bool {
+        return values.contains(where: { $0 == self })
     }
 }
diff --git a/DGElasticPullToRefresh/DGElasticPullToRefreshLoadingViewCircle.swift b/DGElasticPullToRefresh/DGElasticPullToRefreshLoadingViewCircle.swift
index b3cdd2b..90dacc6 100644
--- a/DGElasticPullToRefresh/DGElasticPullToRefreshLoadingViewCircle.swift
+++ b/DGElasticPullToRefresh/DGElasticPullToRefreshLoadingViewCircle.swift
@@ -99,11 +99,11 @@ public class DGElasticPullToRefreshLoadingViewCircle: DGElasticPullToRefreshLoad
         if shapeLayer.animationForKey(kRotationAnimation) != nil { return }
         
         let rotationAnimation = CABasicAnimation(keyPath: "transform.rotation.z")
-        rotationAnimation.toValue = CGFloat(2 * M_PI) + currentDegree()
+        rotationAnimation.toValue = CGFloat(2 * Double.pi) + currentDegree()
         rotationAnimation.duration = 1.0
         rotationAnimation.repeatCount = Float.infinity
         rotationAnimation.removedOnCompletion = false
-        rotationAnimation.fillMode = kCAFillModeForwards
+        rotationAnimation.fillMode = CAMediaTimingFillMode.forwards
         shapeLayer.addAnimation(rotationAnimation, forKey: kRotationAnimation)
     }
     
diff --git a/DGElasticPullToRefresh/DGElasticPullToRefreshView.swift b/DGElasticPullToRefresh/DGElasticPullToRefreshView.swift
index 152af8c..80ec6bd 100644
--- a/DGElasticPullToRefresh/DGElasticPullToRefreshView.swift
+++ b/DGElasticPullToRefresh/DGElasticPullToRefreshView.swift
@@ -124,7 +124,7 @@ public class DGElasticPullToRefreshView: UIView {
         super.init(frame: CGRect.zero)
         
         displayLink = CADisplayLink(target: self, selector: Selector("displayLinkTick"))
-        displayLink.addToRunLoop(NSRunLoop.mainRunLoop(), forMode: NSRunLoopCommonModes)
+        displayLink.add(to: RunLoop.main, forMode: RunLoop.Mode.common)
         displayLink.paused = true
         
         shapeLayer.backgroundColor = UIColor.clearColor().CGColor
@@ -141,7 +141,7 @@ public class DGElasticPullToRefreshView: UIView {
         addSubview(r2ControlPointView)
         addSubview(r3ControlPointView)
         
-        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("applicationWillEnterForeground"), name: UIApplicationWillEnterForegroundNotification, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(DGElasticPullToRefreshView.applicationWillEnterForeground), name: UIApplication.willEnterForegroundNotification, object: nil)
     }
 
     required public init?(coder aDecoder: NSCoder) {
@@ -175,8 +175,10 @@ public class DGElasticPullToRefreshView: UIView {
         } else if keyPath == DGElasticPullToRefreshConstants.KeyPaths.Frame {
             layoutSubviews()
         } else if keyPath == DGElasticPullToRefreshConstants.KeyPaths.PanGestureRecognizerState {
-            if let gestureState = scrollView()?.panGestureRecognizer.state where gestureState.dg_isAnyOf([.Ended, .Cancelled, .Failed]) {
-                scrollViewDidChangeContentOffset(dragging: false)
+            if let gestureState = scrollView()?.panGestureRecognizer.state {
+                if gestureState == .ended || gestureState == .cancelled || gestureState == .failed {
+                    scrollViewDidChangeContentOffset(dragging: false)
+                }
             }
         }
     }
@@ -184,7 +186,7 @@ public class DGElasticPullToRefreshView: UIView {
     // MARK: -
     // MARK: Notifications
     
-    func applicationWillEnterForeground() {
+    @objc func applicationWillEnterForeground() {
         if state == .Loading {
             layoutSubviews()
         }
@@ -336,7 +338,7 @@ public class DGElasticPullToRefreshView: UIView {
         displayLink.paused = true
     }
     
-    func displayLinkTick() {
+    @objc func displayLinkTick() {
         let width = bounds.width
         var height: CGFloat = 0.0