diff --git a/Cheetah.xcodeproj/project.pbxproj b/Cheetah.xcodeproj/project.pbxproj
index 6a326e3..3c1f7f8 100644
--- a/Cheetah.xcodeproj/project.pbxproj
+++ b/Cheetah.xcodeproj/project.pbxproj
@@ -227,7 +227,7 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 1000;
-				LastUpgradeCheck = 1000;
+				LastUpgradeCheck = 1110;
 				ORGANIZATIONNAME = "Suguru Namura";
 				TargetAttributes = {
 					6F96CF661B8436F80014443A = {
@@ -236,7 +236,7 @@
 					};
 					6F96CF701B8436F80014443A = {
 						CreatedOnToolsVersion = 7.0;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1110;
 					};
 					ED8C38122175D484006203F0 = {
 						CreatedOnToolsVersion = 10.0;
@@ -246,7 +246,7 @@
 			};
 			buildConfigurationList = 6F96CF611B8436F80014443A /* Build configuration list for PBXProject "Cheetah" */;
 			compatibilityVersion = "Xcode 3.2";
-			developmentRegion = English;
+			developmentRegion = en;
 			hasScannedForEncodings = 0;
 			knownRegions = (
 				en,
@@ -397,7 +397,7 @@
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
@@ -449,7 +449,7 @@
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -474,8 +474,8 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_SWIFT3_OBJC_INFERENCE = On;
-				SWIFT_VERSION = 4.2;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -495,8 +495,8 @@
 				PRODUCT_BUNDLE_IDENTIFIER = io.github.suguru.Cheetah;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
-				SWIFT_SWIFT3_OBJC_INFERENCE = On;
-				SWIFT_VERSION = 4.2;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};
@@ -507,8 +507,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = io.github.suguru.CheetahTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = On;
-				SWIFT_VERSION = 4.2;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -519,8 +519,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = io.github.suguru.CheetahTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = On;
-				SWIFT_VERSION = 4.2;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};
@@ -560,7 +560,8 @@
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
-				SWIFT_VERSION = 4.2;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 3;
 				TVOS_DEPLOYMENT_TARGET = 11.0;
 			};
@@ -600,7 +601,8 @@
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 4.2;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 3;
 				TVOS_DEPLOYMENT_TARGET = 11.0;
 			};
diff --git a/Cheetah.xcodeproj/xcshareddata/xcschemes/Cheetah-tvOS.xcscheme b/Cheetah.xcodeproj/xcshareddata/xcschemes/Cheetah-tvOS.xcscheme
index 31c182d..6a2aba3 100644
--- a/Cheetah.xcodeproj/xcshareddata/xcschemes/Cheetah-tvOS.xcscheme
+++ b/Cheetah.xcodeproj/xcshareddata/xcschemes/Cheetah-tvOS.xcscheme
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1000"
+   LastUpgradeVersion = "1110"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -29,8 +29,6 @@
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
       </Testables>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </TestAction>
    <LaunchAction
       buildConfiguration = "Debug"
@@ -51,8 +49,6 @@
             ReferencedContainer = "container:Cheetah.xcodeproj">
          </BuildableReference>
       </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
       buildConfiguration = "Release"
diff --git a/Cheetah.xcodeproj/xcshareddata/xcschemes/Cheetah.xcscheme b/Cheetah.xcodeproj/xcshareddata/xcschemes/Cheetah.xcscheme
index b538b57..c02c021 100644
--- a/Cheetah.xcodeproj/xcshareddata/xcschemes/Cheetah.xcscheme
+++ b/Cheetah.xcodeproj/xcshareddata/xcschemes/Cheetah.xcscheme
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1000"
+   LastUpgradeVersion = "1110"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -27,6 +27,15 @@
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       shouldUseLaunchSchemeArgsEnv = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "6F96CF661B8436F80014443A"
+            BuildableName = "Cheetah.framework"
+            BlueprintName = "Cheetah"
+            ReferencedContainer = "container:Cheetah.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
       <Testables>
          <TestableReference
             skipped = "NO">
@@ -39,17 +48,6 @@
             </BuildableReference>
          </TestableReference>
       </Testables>
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "6F96CF661B8436F80014443A"
-            BuildableName = "Cheetah.framework"
-            BlueprintName = "Cheetah"
-            ReferencedContainer = "container:Cheetah.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </TestAction>
    <LaunchAction
       buildConfiguration = "Debug"
@@ -70,8 +68,6 @@
             ReferencedContainer = "container:Cheetah.xcodeproj">
          </BuildableReference>
       </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
       buildConfiguration = "Release"
diff --git a/Cheetah/Bezier.swift b/Cheetah/Bezier.swift
index c3e56b7..83c7969 100644
--- a/Cheetah/Bezier.swift
+++ b/Cheetah/Bezier.swift
@@ -47,11 +47,11 @@ struct UnitBezier {
         t2 = x
         for _ in 0..<8 {
             x2 = sampleCurveX(t2) - x
-            if fabs(x2) < epsilon {
+            if abs(x2) < epsilon {
                 return t2
             }
             d2 = sampleCurveDerivativeX(t2)
-            if fabs(x2) < 1e-6 {
+            if abs(x2) < 1e-6 {
                 break
             }
             t2 = t2 - x2 / d2
@@ -71,7 +71,7 @@ struct UnitBezier {
         
         while t0 < t1 {
             x2 = sampleCurveX(t2)
-            if fabs(x2 - x) < epsilon {
+            if abs(x2 - x) < epsilon {
                 return t2
             }
             if x > x2 {
diff --git a/Cheetah/CheetahManager.swift b/Cheetah/CheetahManager.swift
index f6279c9..139287a 100644
--- a/Cheetah/CheetahManager.swift
+++ b/Cheetah/CheetahManager.swift
@@ -10,7 +10,7 @@ import UIKit
 
 open class CheetahManager {
     
-    open static let sharedInstance = CheetahManager()
+    public static let sharedInstance = CheetahManager()
     
     var cheetahs = [UInt32 : Cheetah]()
     var counter: UInt32
diff --git a/Cheetah/Easings.swift b/Cheetah/Easings.swift
index e53cb1f..dc89e10 100644
--- a/Cheetah/Easings.swift
+++ b/Cheetah/Easings.swift
@@ -10,7 +10,7 @@ import UIKit
 
 public typealias Easing = (_ t:CGFloat, _ b:CGFloat, _ c:CGFloat) -> CGFloat
 
-private let F_PI = CGFloat(M_PI)
+private let F_PI = CGFloat(Double.pi)
 
 // Calculate cubic bezier curve
 public struct Easings {
diff --git a/Cheetah/UIView+CheetahAnimation.swift b/Cheetah/UIView+CheetahAnimation.swift
index 8ba95fe..1f9b709 100644
--- a/Cheetah/UIView+CheetahAnimation.swift
+++ b/Cheetah/UIView+CheetahAnimation.swift
@@ -10,7 +10,7 @@ import UIKit
 
 var cheetahAssociationKey = "cheetahAssociation"
 
-public extension UIView {
+extension UIView {
     
     public var cheetah: Cheetah {
         get {