diff --git a/Example/ExampleSnapshotTests/_Helper/Snapshotting+WindowedImage.swift b/Example/ExampleSnapshotTests/_Helper/Snapshotting+WindowedImage.swift
index cd6dbf2..5dca880 100644
--- a/Example/ExampleSnapshotTests/_Helper/Snapshotting+WindowedImage.swift
+++ b/Example/ExampleSnapshotTests/_Helper/Snapshotting+WindowedImage.swift
@@ -8,6 +8,8 @@
 
 import SnapshotTesting
 
+@testable import GradientLoadingBar
+
 // MARK: - Config
 
 private enum Config {
@@ -25,7 +27,7 @@ extension Snapshotting where Value: UIViewController, Format == UIImage {
             Async<UIImage> { callback in
                 UIView.setAnimationsEnabled(false)
 
-                guard let keyWindow = UIApplication.shared.windows.first(where: { $0.isKeyWindow }) else {
+                guard let keyWindow = UIApplication.shared.keyWindowInConnectedScenes else {
                     fatalError("⚠️ – Failed to get key window from application!")
                 }
                 keyWindow.rootViewController = viewController
diff --git a/Example/ExampleTests/ViewModel/GradientLoadingBarViewModelTestCase.swift b/Example/ExampleTests/ViewModel/GradientLoadingBarViewModelTestCase.swift
index 3f73e1f..2b923e0 100644
--- a/Example/ExampleTests/ViewModel/GradientLoadingBarViewModelTestCase.swift
+++ b/Example/ExampleTests/ViewModel/GradientLoadingBarViewModelTestCase.swift
@@ -47,9 +47,8 @@ final class GradientLoadingBarViewModelTestCase: XCTestCase {
 
     func test_initializer_shouldSetupSuperviewObservable_withKeyWindow() {
         // Given
-        let keyWindow = KeyWindow()
-        let passiveWindow = PassiveWindow()
-        sharedApplicationMock.windows = [keyWindow, passiveWindow]
+        let keyWindow = UIWindow()
+        sharedApplicationMock.keyWindowInConnectedScenes = keyWindow
 
         // When
         let viewModel = GradientLoadingBarViewModel(sharedApplication: sharedApplicationMock,
@@ -61,15 +60,15 @@ final class GradientLoadingBarViewModelTestCase: XCTestCase {
 
     func test_initializer_shouldSetupSuperviewObservable_afterUIWindowDidBecomeKeyNotification() {
         // Given
-        let keyWindow = KeyWindow()
-        let passiveWindow = PassiveWindow()
-        sharedApplicationMock.windows = [passiveWindow]
+        sharedApplicationMock.keyWindowInConnectedScenes = nil
 
         let viewModel = GradientLoadingBarViewModel(sharedApplication: sharedApplicationMock,
                                                     notificationCenter: notificationCenter)
 
         // When
-        sharedApplicationMock.windows.append(keyWindow)
+        let keyWindow = UIWindow()
+        sharedApplicationMock.keyWindowInConnectedScenes = keyWindow
+
         notificationCenter.post(name: UIWindow.didBecomeKeyNotification,
                                 object: nil)
 
@@ -79,9 +78,8 @@ final class GradientLoadingBarViewModelTestCase: XCTestCase {
 
     func test_deinit_shouldResetSuperviewObservable_withNil() {
         // Given
-        let keyWindow = KeyWindow()
-        let passiveWindow = PassiveWindow()
-        sharedApplicationMock.windows = [keyWindow, passiveWindow]
+        let keyWindow = UIWindow()
+        sharedApplicationMock.keyWindowInConnectedScenes = keyWindow
 
         var viewModel: GradientLoadingBarViewModel? = GradientLoadingBarViewModel(sharedApplication: sharedApplicationMock,
                                                                                   notificationCenter: notificationCenter)
@@ -108,18 +106,8 @@ final class GradientLoadingBarViewModelTestCase: XCTestCase {
     }
 }
 
-// MARK: - Helpers
-
-private final class KeyWindow: UIWindow {
-    override var isKeyWindow: Bool { true }
-}
-
-private final class PassiveWindow: UIWindow {
-    override var isKeyWindow: Bool { false }
-}
-
 // MARK: - Mocks
 
 private final class SharedApplicationMock: UIApplicationProtocol {
-    var windows = [UIWindow]()
+    var keyWindowInConnectedScenes: UIWindow?
 }
diff --git a/Example/ExampleTests/Views/GradientActivityIndicatorView+AnimateIsHiddenTestCase.swift b/Example/ExampleTests/Views/GradientActivityIndicatorView+AnimateIsHiddenTestCase.swift
index 30696c4..c289d88 100644
--- a/Example/ExampleTests/Views/GradientActivityIndicatorView+AnimateIsHiddenTestCase.swift
+++ b/Example/ExampleTests/Views/GradientActivityIndicatorView+AnimateIsHiddenTestCase.swift
@@ -24,7 +24,7 @@ final class GradientActivityIndicatorViewAnimateIsHiddenTestCase: XCTestCase {
 
         // In order for UIView animations to be executed correctly, the corresponding view has to be attached to a visible window.
         // Therefore we're gonna use the current key-window, add our testing view here in `setUp()` and remove it later in `tearDown()`.
-        window = UIApplication.shared.windows.first { $0.isKeyWindow }
+        window = UIApplication.shared.keyWindowInConnectedScenes
 
         gradientActivityIndicatorView = GradientActivityIndicatorView()
         window.addSubview(gradientActivityIndicatorView)
diff --git a/GradientLoadingBar/ViewModel/GradientLoadingBarViewModel.swift b/GradientLoadingBar/ViewModel/GradientLoadingBarViewModel.swift
index 71c74c2..5d4e740 100644
--- a/GradientLoadingBar/ViewModel/GradientLoadingBarViewModel.swift
+++ b/GradientLoadingBar/ViewModel/GradientLoadingBarViewModel.swift
@@ -34,7 +34,7 @@ final class GradientLoadingBarViewModel {
         self.sharedApplication = sharedApplication
         self.notificationCenter = notificationCenter
 
-        if let keyWindow = sharedApplication.windows.first(where: { $0.isKeyWindow }) {
+        if let keyWindow = sharedApplication.keyWindowInConnectedScenes {
             superviewSubject.value = keyWindow
         }
 
@@ -56,7 +56,7 @@ final class GradientLoadingBarViewModel {
     // MARK: - Private methods
 
     @objc private func didReceiveUIWindowDidBecomeKeyNotification(_: Notification) {
-        guard let keyWindow = sharedApplication.windows.first(where: { $0.isKeyWindow }) else { return }
+        guard let keyWindow = sharedApplication.keyWindowInConnectedScenes else { return }
 
         superviewSubject.value = keyWindow
     }
@@ -66,7 +66,21 @@ final class GradientLoadingBarViewModel {
 
 /// This allows mocking `UIApplication` in tests.
 protocol UIApplicationProtocol: AnyObject {
-    var windows: [UIWindow] { get }
+    var keyWindowInConnectedScenes: UIWindow? { get }
 }
 
-extension UIApplication: UIApplicationProtocol {}
+extension UIApplication: UIApplicationProtocol {
+    /// Returns the current key window across multiple iOS versions.
+    var keyWindowInConnectedScenes: UIWindow? {
+        guard #available(iOS 15.0, *) else {
+            return windows.first { $0.isKeyWindow }
+        }
+
+        // Starting from iOS 15.0 we need to use `UIWindowScene.windows` on a relevant window scene instead.
+        // Source: https://stackoverflow.com/a/58031897
+        return connectedScenes
+            .compactMap { $0 as? UIWindowScene }
+            .flatMap(\.windows)
+            .first { $0.isKeyWindow }
+    }
+}