diff --git a/DOFavoriteButton/DOFavoriteButton.swift b/DOFavoriteButton/DOFavoriteButton.swift
index 47e6d9d..5c77f11 100644
--- a/DOFavoriteButton/DOFavoriteButton.swift
+++ b/DOFavoriteButton/DOFavoriteButton.swift
@@ -128,7 +128,7 @@ open class DOFavoriteButton: UIButton {
         circleShape.mask = circleMask
 
         let maskPath = UIBezierPath(rect: imageFrame)
-        maskPath.addArc(withCenter: imgCenterPoint, radius: 0.1, startAngle: CGFloat(0.0), endAngle: CGFloat(M_PI * 2), clockwise: true)
+        maskPath.addArc(withCenter: imgCenterPoint, radius: 0.1, startAngle: CGFloat(0.0), endAngle: CGFloat(Double.pi * 2), clockwise: true)
         circleMask.path = maskPath.cgPath
 
         //===============
@@ -155,7 +155,7 @@ open class DOFavoriteButton: UIButton {
             line.strokeStart = 0.0
             line.strokeEnd = 0.0
             line.opacity = 0.0
-            line.transform = CATransform3DMakeRotation(CGFloat(M_PI) / 5 * (CGFloat(i) * 2 + 1), 0.0, 0.0, 1.0)
+            line.transform = CATransform3DMakeRotation(CGFloat(Double.pi) / 5 * (CGFloat(i) * 2 + 1), 0.0, 0.0, 1.0)
             self.layer.addSublayer(line)
             lines.append(line)
         }
@@ -345,19 +345,19 @@ open class DOFavoriteButton: UIButton {
         self.addTarget(self, action: #selector(DOFavoriteButton.touchCancel(_:)), for: UIControlEvents.touchCancel)
     }
 
-    func touchDown(_ sender: DOFavoriteButton) {
+    @objc func touchDown(_ sender: DOFavoriteButton) {
         self.layer.opacity = 0.4
     }
-    func touchUpInside(_ sender: DOFavoriteButton) {
+    @objc func touchUpInside(_ sender: DOFavoriteButton) {
         self.layer.opacity = 1.0
     }
-    func touchDragExit(_ sender: DOFavoriteButton) {
+    @objc func touchDragExit(_ sender: DOFavoriteButton) {
         self.layer.opacity = 1.0
     }
-    func touchDragEnter(_ sender: DOFavoriteButton) {
+    @objc func touchDragEnter(_ sender: DOFavoriteButton) {
         self.layer.opacity = 0.4
     }
-    func touchCancel(_ sender: DOFavoriteButton) {
+    @objc func touchCancel(_ sender: DOFavoriteButton) {
         self.layer.opacity = 1.0
     }