diff --git a/AKImageCropperView/AKImageCropperView.swift b/AKImageCropperView/AKImageCropperView.swift
index c13c531..5d58f02 100644
--- a/AKImageCropperView/AKImageCropperView.swift
+++ b/AKImageCropperView/AKImageCropperView.swift
@@ -40,7 +40,7 @@ open class AKImageCropperView: UIView, UIScrollViewDelegate, UIGestureRecognizer
     fileprivate var reversedRect: CGRect {
         return CGRect(
             origin  : .zero,
-            size    : ((angle / M_PI_2).truncatingRemainder(dividingBy: 2)) == 1
+            size    : ((angle / Double.pi/2).truncatingRemainder(dividingBy: 2)) == 1
                 ? CGSize(width: frame.size.height, height: frame.size.width)
                 : frame.size)
     }
@@ -52,19 +52,19 @@ open class AKImageCropperView: UIView, UIScrollViewDelegate, UIGestureRecognizer
         var newEdgeInsets: UIEdgeInsets
         
         switch angle {
-        case M_PI_2:
+        case Double.pi/2:
             newEdgeInsets = UIEdgeInsetsMake(
                 minEdgeInsets.right,
                 minEdgeInsets.top,
                 minEdgeInsets.left,
                 minEdgeInsets.bottom)
-        case M_PI:
+        case Double.pi:
             newEdgeInsets = UIEdgeInsetsMake(
                 minEdgeInsets.bottom,
                 minEdgeInsets.right,
                 minEdgeInsets.top,
                 minEdgeInsets.left)
-        case M_PI_2 * 3:
+        case Double.pi/2 * 3:
             newEdgeInsets = UIEdgeInsetsMake(
                 minEdgeInsets.left,
                 minEdgeInsets.bottom,
@@ -563,7 +563,7 @@ open class AKImageCropperView: UIView, UIScrollViewDelegate, UIGestureRecognizer
     
     open func rotate(_ angle: Double, withDuration duration: TimeInterval = 0, options: UIViewAnimationOptions = .curveEaseInOut, completion: ((Bool) -> Void)? = nil) {
         
-        guard angle.truncatingRemainder(dividingBy: M_PI_2) == 0 else {
+        guard angle.truncatingRemainder(dividingBy: Double.pi/2) == 0 else {
             return
         }
         
diff --git a/AKImageCropperViewExample/CropperViewController.swift b/AKImageCropperViewExample/CropperViewController.swift
index e3ada4d..d69e593 100644
--- a/AKImageCropperViewExample/CropperViewController.swift
+++ b/AKImageCropperViewExample/CropperViewController.swift
@@ -86,7 +86,7 @@ final class CropperViewController: UIViewController {
     
     @IBAction func showHideOverlayAction(_ sender: AnyObject) {
         
-        if cropView.isoverlayViewActive {
+        if cropView.isOverlayViewActive {
             
             cropView.hideOverlayView(animationDuration: 0.3)
             
@@ -111,11 +111,11 @@ final class CropperViewController: UIViewController {
     
     @IBAction func rotateAction(_ sender: AnyObject) {
 
-        angle += M_PI_2
+        angle += Double.pi/2
         
         cropView.rotate(angle, withDuration: 0.3, completion: { _ in
             
-            if self.angle == 2 * M_PI {
+            if self.angle == 2 * Double.pi {
                 self.angle = 0.0
             }
         })
diff --git a/AKImageCropperViewExample/CustomImageCropperOverlayView.swift b/AKImageCropperViewExample/CustomImageCropperOverlayView.swift
index 69dbc4d..e4be37a 100644
--- a/AKImageCropperViewExample/CustomImageCropperOverlayView.swift
+++ b/AKImageCropperViewExample/CustomImageCropperOverlayView.swift
@@ -30,7 +30,7 @@ final class CustomImageCropperOverlayView: AKImageCropperOverlayView {
             arcCenter:  CGPoint(x: touchView.bounds.midX, y: touchView.bounds.midY),
             radius: width,
             startAngle: 0.0,
-            endAngle: CGFloat(M_PI * 2),
+            endAngle: CGFloat(Double.pi * 2),
             clockwise: true)
 
         layer.path = circlePath.cgPath