diff --git a/MacawTests/Animation/DelayedAnimationTests.swift b/MacawTests/Animation/DelayedAnimationTests.swift
index 7c6b1b37..adcbc23c 100644
--- a/MacawTests/Animation/DelayedAnimationTests.swift
+++ b/MacawTests/Animation/DelayedAnimationTests.swift
@@ -6,25 +6,28 @@
 //  Copyright © 2017 Exyte. All rights reserved.
 //
 
-#if os(iOS)
-
 import XCTest
+#if os(OSX)
+@testable import MacawOSX
+#endif
+
+#if os(iOS)
 @testable import Macaw
+#endif
 
 class DelayedAnimationTests: XCTestCase {
     
-    
     var testView: MacawView!
     var testGroup: Group!
-    var window: UIWindow!
+    var window: MWindow!
     
     override func setUp() {
         super.setUp()
         
         testGroup = [Shape(form:Rect(x: 0.0, y: 0.0, w: 0.0, h: 0.0))].group()
-        testView = MacawView(node: testGroup, frame: CGRect.zero)
+        testView = MacawView(node: testGroup, frame: .zero)
         
-        window = UIWindow()
+        window = MWindow()
         window.addSubview(testView)
     }
     
@@ -54,5 +57,3 @@ class DelayedAnimationTests: XCTestCase {
         XCTAssert(animation.paused && !animation.manualStop, "Wrong animation state on pause")
     }
 }
-
-#endif
diff --git a/Source/platform/iOS/Common_iOS.swift b/Source/platform/iOS/Common_iOS.swift
index d271ed47..219342fe 100644
--- a/Source/platform/iOS/Common_iOS.swift
+++ b/Source/platform/iOS/Common_iOS.swift
@@ -11,6 +11,7 @@ import Foundation
 #if os(iOS)
 import UIKit
 
+public typealias MWindow = UIWindow
 public typealias MRectCorner = UIRectCorner
 public typealias MFont = UIFont
 public typealias MFontDescriptor = UIFontDescriptor
diff --git a/Source/platform/macOS/Common_macOS.swift b/Source/platform/macOS/Common_macOS.swift
index 3fdca8c1..b987e957 100644
--- a/Source/platform/macOS/Common_macOS.swift
+++ b/Source/platform/macOS/Common_macOS.swift
@@ -12,6 +12,7 @@ import Foundation
 import Cocoa
 import Quartz
 
+public typealias MWindow = NSWindow
 public typealias MFont = NSFont
 public typealias MFontDescriptor = NSFontDescriptor
 public typealias MColor = NSColor
@@ -176,4 +177,11 @@ extension CGContext {
     }
 }
 
+extension NSWindow {
+
+    func addSubview(_ subview: NSView) {
+        contentView?.addSubview(subview)
+    }
+}
+
 #endif