diff --git a/stdlib/public/SDK/Foundation/AffineTransform.swift b/stdlib/public/SDK/Foundation/AffineTransform.swift
index 82ef2f7a2541a..34925d058fa1a 100644
--- a/stdlib/public/SDK/Foundation/AffineTransform.swift
+++ b/stdlib/public/SDK/Foundation/AffineTransform.swift
@@ -124,8 +124,8 @@ public struct AffineTransform : ReferenceConvertible, Hashable, CustomStringConv
          [    0       0    1 ]
      */
     public init(rotationByDegrees angle: CGFloat) {
-        let α = Double(angle) * M_PI / 180.0
-        self.init(rotationByRadians: CGFloat(α))
+        let α = angle * .pi / 180.0
+        self.init(rotationByRadians: α)
     }
     
     /**
@@ -153,8 +153,8 @@ public struct AffineTransform : ReferenceConvertible, Hashable, CustomStringConv
          [    0       0    1 ]
      */
     public mutating func rotate(byDegrees angle: CGFloat) {
-        let α = Double(angle) * M_PI / 180.0
-        return rotate(byRadians: CGFloat(α))
+        let α = angle * .pi / 180.0
+        return rotate(byRadians: α)
     }
     
     /**
diff --git a/test/stdlib/TestAffineTransform.swift b/test/stdlib/TestAffineTransform.swift
index 29ba030716078..041a5322eee3e 100644
--- a/test/stdlib/TestAffineTransform.swift
+++ b/test/stdlib/TestAffineTransform.swift
@@ -169,19 +169,19 @@ class TestAffineTransform : TestAffineTransformSuper {
         checkPointTransformation(noop, point: point, expectedPoint: point)
         
         var tenEighty = AffineTransform.identity
-        tenEighty.rotate(byRadians: CGFloat(6 * M_PI))
+        tenEighty.rotate(byRadians: 6 * .pi)
         checkPointTransformation(tenEighty, point: point, expectedPoint: point)
         
         var rotateCounterClockwise = AffineTransform.identity
-        rotateCounterClockwise.rotate(byRadians: CGFloat(M_PI_2))
+        rotateCounterClockwise.rotate(byRadians: .pi / 2)
         checkPointTransformation(rotateCounterClockwise, point: point, expectedPoint: NSPoint(x: CGFloat(-10.0), y: CGFloat(10.0)))
         
         var rotateClockwise = AffineTransform.identity
-        rotateClockwise.rotate(byRadians: CGFloat(-M_PI_2))
+        rotateClockwise.rotate(byRadians: -.pi / 2)
         checkPointTransformation(rotateClockwise, point: point, expectedPoint: NSPoint(x: CGFloat(10.0), y: CGFloat(-10.0)))
         
         var reflectAboutOrigin = AffineTransform.identity
-        reflectAboutOrigin.rotate(byRadians: CGFloat(M_PI))
+        reflectAboutOrigin.rotate(byRadians: .pi)
         checkPointTransformation(reflectAboutOrigin, point: point, expectedPoint: NSPoint(x: CGFloat(-10.0), y: CGFloat(-10.0)))
     }