diff --git a/Package.swift b/Package.swift
new file mode 100755
index 0000000..9cb20b4
--- /dev/null
+++ b/Package.swift
@@ -0,0 +1,23 @@
+// swift-tools-version:5.1
+import PackageDescription
+
+let package = Package(
+    name: "PullToRefresh",
+    platforms: [
+        .iOS(.v8),
+    ],
+    products: [
+        .library(name: "PullToRefresh", targets: ["PullToRefresh"])
+    ],
+    dependencies: [
+    ],
+    targets: [
+        .target(
+            name: "PullToRefresh",
+            dependencies: [
+            ],
+            path: "PullToRefresh"
+        )
+    ],
+    swiftLanguageVersions: [ .v5 ]
+)
diff --git a/PullToRefresh/DefaultRefreshView.swift b/PullToRefresh/DefaultRefreshView.swift
index 929d3eb..a93e9fa 100644
--- a/PullToRefresh/DefaultRefreshView.swift
+++ b/PullToRefresh/DefaultRefreshView.swift
@@ -7,6 +7,7 @@
 //
 
 import UIKit
+import CoreGraphics
 
 class DefaultRefreshView: UIView {
     
diff --git a/PullToRefresh/DefaultViewAnimator.swift b/PullToRefresh/DefaultViewAnimator.swift
index 63d9d62..bdb3447 100644
--- a/PullToRefresh/DefaultViewAnimator.swift
+++ b/PullToRefresh/DefaultViewAnimator.swift
@@ -7,6 +7,7 @@
 //
 
 import Foundation
+import CoreGraphics
 
 class DefaultViewAnimator: RefreshViewAnimator {
     
diff --git a/PullToRefresh/PullToRefresh.swift b/PullToRefresh/PullToRefresh.swift
index 8ef924f..1ce037e 100644
--- a/PullToRefresh/PullToRefresh.swift
+++ b/PullToRefresh/PullToRefresh.swift
@@ -7,6 +7,7 @@
 //
 
 import UIKit
+import CoreGraphics
 
 public enum Position {
     
diff --git a/PullToRefresh/State.swift b/PullToRefresh/State.swift
index fac13f5..e475fe1 100644
--- a/PullToRefresh/State.swift
+++ b/PullToRefresh/State.swift
@@ -7,6 +7,7 @@
 //
 
 import Foundation
+import CoreGraphics
 
 public enum State: Equatable, CustomStringConvertible {
     
diff --git a/PullToRefresher.podspec b/PullToRefresher.podspec
index b8390fe..6d5f432 100644
--- a/PullToRefresher.podspec
+++ b/PullToRefresher.podspec
@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name         = "PullToRefresher"
-  s.version      = "3.3"
+  s.version      = "3.3.1"
   s.summary      = "This component implements pure pull-to-refresh logic and you can use it for developing your own pull-to-refresh animations"
   s.homepage     = "http://yalantis.com/blog/how-we-built-customizable-pull-to-refresh-pull-to-cook-soup-animation/"
   s.swift_version = '5.0'