diff --git a/Library/PMAlertController.swift b/Library/PMAlertController.swift
index 2a6819a..d73ab9d 100755
--- a/Library/PMAlertController.swift
+++ b/Library/PMAlertController.swift
@@ -162,11 +162,11 @@ import UIKit
     
     @objc fileprivate func animateDismissWithGravity(_ style: PMAlertActionStyle){
         if gravityDismissAnimation == true{
-            var radian = M_PI
+            var radian = Double.pi
             if style == .default {
-                radian = 2 * M_PI
+                radian = 2 * Double.pi
             }else{
-                radian = -2 * M_PI
+                radian = -2 * Double.pi
             }
             animator = UIDynamicAnimator(referenceView: self.view)