diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Internal/StorefrontAPI/StorefrontAPIMutationsTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Internal/StorefrontAPI/StorefrontAPIMutationsTests.swift
index 6cd2d3e4..7ee4a043 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Internal/StorefrontAPI/StorefrontAPIMutationsTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Internal/StorefrontAPI/StorefrontAPIMutationsTests.swift
@@ -66,11 +66,11 @@ final class StorefrontAPIMutationsTests: XCTestCase {
     // MARK: - Mock URLProtocol for Network Mocking
 
     class MockURLProtocol: URLProtocol {
-        static var mockResponseData: Data?
-        static var mockError: Error?
-        static var mockStatusCode: Int = 200
-        static var capturedRequest: URLRequest?
-        static var capturedRequestBody: Data?
+        nonisolated(unsafe) static var mockResponseData: Data?
+        nonisolated(unsafe) static var mockError: Error?
+        nonisolated(unsafe) static var mockStatusCode: Int = 200
+        nonisolated(unsafe) static var capturedRequest: URLRequest?
+        nonisolated(unsafe) static var capturedRequestBody: Data?
 
         override class func canInit(with _: URLRequest) -> Bool {
             return true
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Internal/StorefrontAPI/StorefrontAPIQueriesTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Internal/StorefrontAPI/StorefrontAPIQueriesTests.swift
index dee78621..ca3569bc 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Internal/StorefrontAPI/StorefrontAPIQueriesTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Internal/StorefrontAPI/StorefrontAPIQueriesTests.swift
@@ -29,11 +29,11 @@ final class StorefrontAPIQueriesTests: XCTestCase {
     // MARK: - Mock URLProtocol for Network Mocking
 
     class MockURLProtocol: URLProtocol {
-        static var mockResponseData: Data?
-        static var mockError: Error?
-        static var mockStatusCode: Int = 200
-        static var capturedRequest: URLRequest?
-        static var capturedRequestBody: Data?
+        nonisolated(unsafe) static var mockResponseData: Data?
+        nonisolated(unsafe) static var mockError: Error?
+        nonisolated(unsafe) static var mockStatusCode: Int = 200
+        nonisolated(unsafe) static var capturedRequest: URLRequest?
+        nonisolated(unsafe) static var capturedRequestBody: Data?
 
         override class func canInit(with _: URLRequest) -> Bool {
             return true
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/TestHelpers.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/TestHelpers.swift
index 1dc688ae..6cd9cfed 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/TestHelpers.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/TestHelpers.swift
@@ -29,6 +29,7 @@ import XCTest
 
 // MARK: - Configuration Helpers
 
+@MainActor
 func XCTAssertThrowsErrorAsync(
     _ expression: @autoclosure () async throws -> some Any,
     _ errorHandler: (Error) -> Void,
@@ -298,7 +299,7 @@ extension StorefrontAPI.Cart {
 /// This class conforms to StorefrontAPIProtocol with not implemented errors
 /// Extend this class and override only the methods you need, per test file
 @available(iOS 16.0, *)
-class MockStorefrontAPI: StorefrontAPIProtocol {
+class MockStorefrontAPI: @unchecked Sendable, StorefrontAPIProtocol {
     func cart(by _: GraphQLScalars.ID) async throws -> StorefrontAPI.Cart? {
         fatalError("cart(by:) not implemented in test. Override this method in your test class.")
     }
@@ -383,7 +384,7 @@ class MockStorefrontAPI: StorefrontAPIProtocol {
 // MARK: - Test StorefrontAPI
 
 @available(iOS 16.0, *)
-class TestStorefrontAPI: MockStorefrontAPI {
+class TestStorefrontAPI: MockStorefrontAPI, @unchecked Sendable {
     var cartResult: Result<StorefrontAPI.Cart?, Error>?
 
     override func cart(by _: GraphQLScalars.ID) async throws -> StorefrontAPI.Cart? {
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/AcceleratedCheckoutButtonsRenderStateTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/AcceleratedCheckoutButtonsRenderStateTests.swift
index 8ca19ac2..adf3ac56 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/AcceleratedCheckoutButtonsRenderStateTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/AcceleratedCheckoutButtonsRenderStateTests.swift
@@ -26,6 +26,7 @@ import SwiftUI
 import XCTest
 
 @available(iOS 17.0, *)
+@MainActor
 final class AcceleratedCheckoutButtonsRenderStateTests: XCTestCase {
     // MARK: - Render State Change Callback Tests
 
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayAuthorizationDelegate/ApplePayAuthorizationDelegateControllerTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayAuthorizationDelegate/ApplePayAuthorizationDelegateControllerTests.swift
index b8e89f4c..5f1f7e75 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayAuthorizationDelegate/ApplePayAuthorizationDelegateControllerTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayAuthorizationDelegate/ApplePayAuthorizationDelegateControllerTests.swift
@@ -635,12 +635,12 @@ final class ApplePayAuthorizationDelegateControllerTests: XCTestCase {
             "\"cost\":{\"totalAmount\":{\"amount\":\"0.00\",\"currencyCode\":\"USD\"}}," +
             "\"discountCodes\":[],\"discountAllocations\":[]}"
 
-        static var failReplace = false
-        static var failDeliveryUpdate = false
-        static var failPrepareForCompletion = false
-        static var returnMappableCartUserError = false
-        static var returnInvalidCart = false
-        static var lastOperation: String?
+        nonisolated(unsafe) static var failReplace = false
+        nonisolated(unsafe) static var failDeliveryUpdate = false
+        nonisolated(unsafe) static var failPrepareForCompletion = false
+        nonisolated(unsafe) static var returnMappableCartUserError = false
+        nonisolated(unsafe) static var returnInvalidCart = false
+        nonisolated(unsafe) static var lastOperation: String?
 
         static func response(for op: String) -> Data {
             if op == "cartPrepareForCompletion" {
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayCallbackTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayCallbackTests.swift
index 99f1bf26..17d4a247 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayCallbackTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayCallbackTests.swift
@@ -26,6 +26,7 @@
 import XCTest
 
 @available(iOS 17.0, *)
+@MainActor
 final class ApplePayCallbackTests: XCTestCase {
     // MARK: - Properties
 
@@ -37,8 +38,8 @@ final class ApplePayCallbackTests: XCTestCase {
 
     // MARK: - Setup
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
 
         // Create mock configuration
         let commonConfig = ShopifyAcceleratedCheckouts.Configuration(
@@ -75,13 +76,13 @@ final class ApplePayCallbackTests: XCTestCase {
         )
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         viewController = nil
         mockConfiguration = nil
         mockIdentifier = nil
         errorExpectation = nil
         cancelExpectation = nil
-        super.tearDown()
+        try await super.tearDown()
     }
 
     // MARK: - Error Callback Tests
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayIntegrationTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayIntegrationTests.swift
index 7adec063..0000e308 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayIntegrationTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayIntegrationTests.swift
@@ -27,6 +27,7 @@ import SwiftUI
 import XCTest
 
 @available(iOS 17.0, *)
+@MainActor
 final class ApplePayIntegrationTests: XCTestCase {
     // MARK: - Properties
 
@@ -37,8 +38,8 @@ final class ApplePayIntegrationTests: XCTestCase {
 
     // MARK: - Setup
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
 
         mockCommonConfiguration = ShopifyAcceleratedCheckouts.Configuration(
             storefrontDomain: "test-shop.myshopify.com",
@@ -69,12 +70,12 @@ final class ApplePayIntegrationTests: XCTestCase {
         )
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         mockConfiguration = nil
         mockCommonConfiguration = nil
         mockApplePayConfiguration = nil
         mockShopSettings = nil
-        super.tearDown()
+        try await super.tearDown()
     }
 
     // MARK: - Integration Tests
@@ -152,7 +153,7 @@ final class ApplePayIntegrationTests: XCTestCase {
             failCount += 1
         }
 
-        let button = await ApplePayButton(
+        let button = ApplePayButton(
             identifier: .cart(cartID: "gid://Shopify/Cart/test-cart"),
             eventHandlers: EventHandlers(checkoutDidFail: failHandler),
             cornerRadius: nil
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayViewControllerTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayViewControllerTests.swift
index 1601a968..c7d5bab3 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayViewControllerTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayViewControllerTests.swift
@@ -27,14 +27,15 @@ import UIKit
 import XCTest
 
 @available(iOS 17.0, *)
+@MainActor
 class ApplePayViewControllerTests: XCTestCase {
     var viewController: MockApplePayViewController!
     var mockConfiguration: ApplePayConfigurationWrapper!
     var mockStorefront: TestStorefrontAPI!
     var mockAuthorizationDelegate: MockApplePayAuthorizationDelegate!
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
 
         // Create mock shop settings
         let paymentSettings = PaymentSettings(
@@ -91,12 +92,12 @@ class ApplePayViewControllerTests: XCTestCase {
         viewController.setMockAuthorizationDelegate(mockAuthorizationDelegate)
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         viewController = nil
         mockConfiguration = nil
         mockStorefront = nil
         mockAuthorizationDelegate = nil
-        super.tearDown()
+        try await super.tearDown()
     }
 
     class MockApplePayAuthorizationDelegate: ApplePayAuthorizationDelegate {
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayViewModifierTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayViewModifierTests.swift
index d720d13a..5a431312 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayViewModifierTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ApplePay/ApplePayViewModifierTests.swift
@@ -27,6 +27,7 @@ import SwiftUI
 import XCTest
 
 @available(iOS 17.0, *)
+@MainActor
 final class ApplePayViewModifierTests: XCTestCase {
     // MARK: - Properties
 
@@ -36,8 +37,8 @@ final class ApplePayViewModifierTests: XCTestCase {
 
     // MARK: - Setup
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
 
         mockConfiguration = ShopifyAcceleratedCheckouts.Configuration(
             storefrontDomain: "test-shop.myshopify.com",
@@ -59,11 +60,11 @@ final class ApplePayViewModifierTests: XCTestCase {
         )
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         mockConfiguration = nil
         mockApplePayConfiguration = nil
         mockShopSettings = nil
-        super.tearDown()
+        try await super.tearDown()
     }
 
     // MARK: - onCancel Modifier Tests
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayButtonTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayButtonTests.swift
index c24355de..dd9e1cc9 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayButtonTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayButtonTests.swift
@@ -27,6 +27,7 @@ import ViewInspector
 import XCTest
 
 @available(iOS 17.0, *)
+@MainActor
 class ShopPayButtonTests: XCTestCase {
     // MARK: - Test Setup
 
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayCallbackTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayCallbackTests.swift
index de681f07..cff41b12 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayCallbackTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayCallbackTests.swift
@@ -26,6 +26,7 @@
 import XCTest
 
 @available(iOS 17.0, *)
+@MainActor
 final class ShopPayCallbackTests: XCTestCase {
     // MARK: - Properties
 
@@ -37,8 +38,8 @@ final class ShopPayCallbackTests: XCTestCase {
 
     // MARK: - Setup
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
 
         mockConfiguration = ShopifyAcceleratedCheckouts.Configuration(
             storefrontDomain: "test-shop.myshopify.com",
@@ -53,13 +54,13 @@ final class ShopPayCallbackTests: XCTestCase {
         )
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         viewController = nil
         mockConfiguration = nil
         mockIdentifier = nil
         errorExpectation = nil
         cancelExpectation = nil
-        super.tearDown()
+        try await super.tearDown()
     }
 
     // MARK: - Error Callback Tests
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayViewControllerTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayViewControllerTests.swift
index 4eadfaa3..18966844 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayViewControllerTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/ShopPay/ShopPayViewControllerTests.swift
@@ -26,15 +26,14 @@ import ShopifyCheckoutKit
 import XCTest
 
 @available(iOS 16.0, *)
-
-@available(iOS 16.0, *)
+@MainActor
 final class ShopPayViewControllerTests: XCTestCase {
     var viewController: MockShopPayViewController!
     var mockConfiguration: ShopifyAcceleratedCheckouts.Configuration!
     var mockStorefront: TestStorefrontAPI!
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
 
         mockConfiguration = ShopifyAcceleratedCheckouts.Configuration(
             storefrontDomain: "test-shop.myshopify.com",
@@ -43,11 +42,11 @@ final class ShopPayViewControllerTests: XCTestCase {
         mockStorefront = TestStorefrontAPI()
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         viewController = nil
         mockConfiguration = nil
         mockStorefront = nil
-        super.tearDown()
+        try await super.tearDown()
     }
 
     @available(iOS 16.0, *)
diff --git a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/WalletControllerTests.swift b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/WalletControllerTests.swift
index 6f5b1d26..8bfc9b0d 100644
--- a/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/WalletControllerTests.swift
+++ b/platforms/swift/Tests/ShopifyAcceleratedCheckoutsTests/Wallets/WalletControllerTests.swift
@@ -27,18 +27,19 @@ import UIKit
 import XCTest
 
 @available(iOS 16.0, *)
+@MainActor
 final class WalletControllerTests: XCTestCase {
     var mockStorefront: TestStorefrontAPI!
     var controller: MockWalletController!
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
         mockStorefront = TestStorefrontAPI()
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         mockStorefront = nil
         controller = nil
-        super.tearDown()
+        try await super.tearDown()
     }
 
     class MockWalletController: WalletController {
diff --git a/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutBridgeTests.swift b/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutBridgeTests.swift
index 4fea9013..08ecdc4f 100644
--- a/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutBridgeTests.swift
+++ b/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutBridgeTests.swift
@@ -25,6 +25,7 @@
 import WebKit
 import XCTest
 
+@MainActor
 class CheckoutBridgeTests: XCTestCase {
     func testReturnsStandardUserAgent() {
         let version = ShopifyCheckoutKit.version
diff --git a/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutViewControllerTests.swift b/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutViewControllerTests.swift
index 9dad35c9..a63fa411 100644
--- a/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutViewControllerTests.swift
+++ b/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutViewControllerTests.swift
@@ -25,13 +25,16 @@
 import WebKit
 import XCTest
 
+@MainActor
 class CheckoutViewDelegateTests: XCTestCase {
     private var customTitle: String?
     private let checkoutURL = URL(string: "https://checkout-sdk.myshopify.com")!
     private var viewController: MockCheckoutWebViewController!
     private var navigationController: UINavigationController!
 
-    override func setUp() {
+    override func setUp() async throws {
+        try await super.setUp()
+        CheckoutWebView.invalidate()
         ShopifyCheckoutKit.configure {
             $0.preloading.enabled = true
             $0.title = customTitle ?? "Checkout"
@@ -43,9 +46,10 @@ class CheckoutViewDelegateTests: XCTestCase {
         navigationController = UINavigationController(rootViewController: viewController)
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
+        CheckoutWebView.invalidate()
         customTitle = nil
-        super.tearDown()
+        try await super.tearDown()
     }
 
     func testTitleIsSetToCheckout() {
@@ -54,7 +58,10 @@ class CheckoutViewDelegateTests: XCTestCase {
 
     func testTitleCanBeCustomized() {
         customTitle = "Custom title"
-        setUp()
+        ShopifyCheckoutKit.configure { $0.title = customTitle ?? "Checkout" }
+        viewController = MockCheckoutWebViewController(
+            checkoutURL: checkoutURL
+        )
         XCTAssertEqual(viewController.title, "Custom title")
     }
 
@@ -207,6 +214,7 @@ class CheckoutViewDelegateTests: XCTestCase {
     }
 }
 
+@MainActor
 protocol Dismissible: AnyObject {
     func dismiss(animated flag: Bool, completion: (() -> Void)?)
 }
diff --git a/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutWebViewControllerTests.swift b/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutWebViewControllerTests.swift
index c6bdb4c6..1f87cbc2 100644
--- a/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutWebViewControllerTests.swift
+++ b/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutWebViewControllerTests.swift
@@ -43,6 +43,7 @@ class TestableCheckoutWebViewController: CheckoutWebViewController {
     }
 }
 
+@MainActor
 class CheckoutWebViewControllerTests: XCTestCase {
     private let url = URL(string: "http://shopify1.shopify.com/checkouts/cn/123")!
     private let multipassURL = URL(string: "http://shopify1.shopify.com/checkouts/cn/123?multipass=token")!
diff --git a/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutWebViewTests.swift b/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutWebViewTests.swift
index 5c3ef62d..997b8fcf 100644
--- a/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutWebViewTests.swift
+++ b/platforms/swift/Tests/ShopifyCheckoutKitTests/CheckoutWebViewTests.swift
@@ -26,13 +26,15 @@ import ShopifyCheckoutProtocol
 import WebKit
 import XCTest
 
+@MainActor
 class CheckoutWebViewTests: XCTestCase {
     private var view: CheckoutWebView!
     private var recovery: CheckoutWebView!
     private var mockDelegate: MockCheckoutWebViewDelegate!
     private var url = URL(string: "http://shopify1.shopify.com/checkouts/cn/123")!
 
-    override func setUp() {
+    override func setUp() async throws {
+        try await super.setUp()
         ShopifyCheckoutKit.configure { $0.preloading.enabled = true }
         view = CheckoutWebView.for(checkout: url)
         mockDelegate = MockCheckoutWebViewDelegate()
@@ -365,7 +367,7 @@ class CheckoutWebViewTests: XCTestCase {
 
     func testDoesNotInstrumentPreloadingTagIfDisabled() throws {
         let webView = LoadedRequestObservableWebView()
-        ShopifyCheckoutKit.configuration.preloading.enabled = false
+        ShopifyCheckoutKit.configure { $0.preloading.enabled = false }
 
         try webView.load(
             checkout: XCTUnwrap(URL(string: "https://checkout-sdk.myshopify.io")),
@@ -379,7 +381,7 @@ class CheckoutWebViewTests: XCTestCase {
     }
 
     func testDetachBridgeCalledOnInit() throws {
-        ShopifyCheckoutKit.configuration.preloading.enabled = false
+        ShopifyCheckoutKit.configure { $0.preloading.enabled = false }
         let url = URL(string: "http://shopify1.shopify.com/checkouts/cn/123")
         let view = try CheckoutWebView.for(checkout: XCTUnwrap(url))
         XCTAssertTrue(view.isBridgeAttached)
@@ -389,7 +391,7 @@ class CheckoutWebViewTests: XCTestCase {
     }
 
     func testCacheIsClearedOnInvalidate() throws {
-        ShopifyCheckoutKit.configuration.preloading.enabled = true
+        ShopifyCheckoutKit.configure { $0.preloading.enabled = true }
         let url = URL(string: "http://shopify1.shopify.com/checkouts/cn/123")
         let view = try CheckoutWebView.for(checkout: XCTUnwrap(url))
         XCTAssertTrue(view.isBridgeAttached)
diff --git a/platforms/swift/Tests/ShopifyCheckoutKitTests/ConfigurationTests.swift b/platforms/swift/Tests/ShopifyCheckoutKitTests/ConfigurationTests.swift
index 4e911619..b2ffac27 100644
--- a/platforms/swift/Tests/ShopifyCheckoutKitTests/ConfigurationTests.swift
+++ b/platforms/swift/Tests/ShopifyCheckoutKitTests/ConfigurationTests.swift
@@ -25,15 +25,16 @@
 import UIKit
 import XCTest
 
+@MainActor
 class ConfigurationTests: XCTestCase {
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
         resetConfigurationState()
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         resetConfigurationState()
-        super.tearDown()
+        try await super.tearDown()
     }
 
     private func resetConfigurationState() {
diff --git a/platforms/swift/Tests/ShopifyCheckoutKitTests/LoggerTests.swift b/platforms/swift/Tests/ShopifyCheckoutKitTests/LoggerTests.swift
index f902ff3e..b55c7396 100644
--- a/platforms/swift/Tests/ShopifyCheckoutKitTests/LoggerTests.swift
+++ b/platforms/swift/Tests/ShopifyCheckoutKitTests/LoggerTests.swift
@@ -25,7 +25,7 @@ import os.log
 @testable import ShopifyCheckoutKit
 import XCTest
 
-class TestableOSLogger: OSLogger {
+class TestableOSLogger: OSLogger, @unchecked Sendable {
     private(set) var capturedMessages: [(message: String, type: OSLogType)] = []
     private let testPrefix: String
     override init() {
@@ -43,17 +43,18 @@ class TestableOSLogger: OSLogger {
     }
 }
 
+@MainActor
 final class OSLoggerTests: XCTestCase {
     var originalConfiguration: Configuration!
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
         originalConfiguration = ShopifyCheckoutKit.configuration
     }
 
-    override func tearDown() {
+    override func tearDown() async throws {
         ShopifyCheckoutKit.setConfiguration(originalConfiguration)
-        super.tearDown()
+        try await super.tearDown()
     }
 
     func test_sharedLogger_whenAccessed_shouldExist() {
diff --git a/platforms/swift/Tests/ShopifyCheckoutKitTests/ShopifyCheckoutKitTests.swift b/platforms/swift/Tests/ShopifyCheckoutKitTests/ShopifyCheckoutKitTests.swift
index 256ce287..68a0307d 100644
--- a/platforms/swift/Tests/ShopifyCheckoutKitTests/ShopifyCheckoutKitTests.swift
+++ b/platforms/swift/Tests/ShopifyCheckoutKitTests/ShopifyCheckoutKitTests.swift
@@ -24,6 +24,7 @@
 @testable import ShopifyCheckoutKit
 import XCTest
 
+@MainActor
 class ShopifyCheckoutKitTests: XCTestCase {
     func test_version_whenAccessed_shouldExist() {
         XCTAssertFalse(ShopifyCheckoutKit.version.isEmpty)
diff --git a/platforms/swift/Tests/ShopifyCheckoutKitTests/SwiftUITests.swift b/platforms/swift/Tests/ShopifyCheckoutKitTests/SwiftUITests.swift
index cf110383..1ea1e78b 100644
--- a/platforms/swift/Tests/ShopifyCheckoutKitTests/SwiftUITests.swift
+++ b/platforms/swift/Tests/ShopifyCheckoutKitTests/SwiftUITests.swift
@@ -24,12 +24,13 @@
 @testable import ShopifyCheckoutKit
 import XCTest
 
+@MainActor
 class CheckoutViewControllerTests: XCTestCase {
     var checkoutURL: URL!
     var checkoutViewController: CheckoutViewController!
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
         checkoutURL = URL(string: "https://www.shopify.com")
         checkoutViewController = CheckoutViewController(checkout: checkoutURL)
     }
@@ -39,12 +40,13 @@ class CheckoutViewControllerTests: XCTestCase {
     }
 }
 
+@MainActor
 class CheckoutSheetTests: XCTestCase {
     var checkoutURL: URL!
     var checkoutSheet: CheckoutSheet!
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
         checkoutURL = URL(string: "https://www.shopify.com")
         checkoutSheet = CheckoutSheet(checkout: checkoutURL)
     }
@@ -81,12 +83,13 @@ class CheckoutSheetTests: XCTestCase {
     }
 }
 
+@MainActor
 class CheckoutConfigurableTests: XCTestCase {
     var checkoutURL: URL!
     var checkoutSheet: CheckoutSheet!
 
-    override func setUp() {
-        super.setUp()
+    override func setUp() async throws {
+        try await super.setUp()
         checkoutURL = URL(string: "https://www.shopify.com")
         checkoutSheet = CheckoutSheet(checkout: checkoutURL)
     }