diff --git a/PHP Monitor.xcodeproj/xcshareddata/xcschemes/PHP Monitor.xcscheme b/PHP Monitor.xcodeproj/xcshareddata/xcschemes/PHP Monitor.xcscheme
index 0ed1bb3..02cf00d 100644
--- a/PHP Monitor.xcodeproj/xcshareddata/xcschemes/PHP Monitor.xcscheme	
+++ b/PHP Monitor.xcodeproj/xcshareddata/xcschemes/PHP Monitor.xcscheme	
@@ -76,7 +76,7 @@
          <EnvironmentVariable
             key = "SLOW_SHELL_MODE"
             value = ""
-            isEnabled = "YES">
+            isEnabled = "NO">
          </EnvironmentVariable>
          <EnvironmentVariable
             key = "PAINT_PHPMON_SWIFTUI_VIEWS"
diff --git a/phpmon/Common/Filesystem/ActiveFileSystem.swift b/phpmon/Common/Filesystem/ActiveFileSystem.swift
index 7ffee2c..e9ae75d 100644
--- a/phpmon/Common/Filesystem/ActiveFileSystem.swift
+++ b/phpmon/Common/Filesystem/ActiveFileSystem.swift
@@ -16,8 +16,7 @@ class ActiveFileSystem {
     static var shared: FileSystemProtocol = RealFileSystem()
 
     public static func useTestable(_ files: [String: FakeFile]) {
-        // TODO
-        // Self.shared = TestableShell(expectations: expectations)
+        Self.shared = TestableFileSystem(files: files)
     }
 
     public static func useSystem() {
diff --git a/phpmon/Common/Testables/TestableConfigurations.swift b/phpmon/Common/Testables/TestableConfigurations.swift
index 6d490e7..f5525d0 100644
--- a/phpmon/Common/Testables/TestableConfigurations.swift
+++ b/phpmon/Common/Testables/TestableConfigurations.swift
@@ -12,6 +12,11 @@ struct TestableConfiguration {
     let architecture: String
     let filesystem: [String: FakeFile]
     let shellOutput: [String: BatchFakeShellOutput]
+
+    func apply() {
+        ActiveShell.useTestable(shellOutput)
+        ActiveFileSystem.useTestable(filesystem)
+    }
 }
 
 // swiftlint:disable colon trailing_comma
diff --git a/phpmon/Common/Testables/TestableFileSystem.swift b/phpmon/Common/Testables/TestableFileSystem.swift
index 1e2f1b9..f814e59 100644
--- a/phpmon/Common/Testables/TestableFileSystem.swift
+++ b/phpmon/Common/Testables/TestableFileSystem.swift
@@ -9,6 +9,12 @@
 import Foundation
 
 class TestableFileSystem: FileSystemProtocol {
+    init(files: [String: FakeFile]) {
+        self.files = files
+    }
+
+    var files: [String: FakeFile]
+
     func isExecutableFile(_ path: String) -> Bool {
         // TODO
         return false
diff --git a/phpmon/Domain/App/AppDelegate.swift b/phpmon/Domain/App/AppDelegate.swift
index c34fc74..a446586 100644
--- a/phpmon/Domain/App/AppDelegate.swift
+++ b/phpmon/Domain/App/AppDelegate.swift
@@ -57,13 +57,12 @@ class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCenterDele
      */
     override init() {
         logger.verbosity = .info
+
         #if DEBUG
         logger.verbosity = .performance
-
-        // TODO: Enable to fake broken setup during testing
-        // ActiveShell.useTestable(Testables.working.shellOutput)
-
+        TestableConfigurations.working.apply()
         #endif
+
         if CommandLine.arguments.contains("--v") {
             logger.verbosity = .performance
             Log.info("Extra verbose mode has been activated.")
diff --git a/phpmon/Domain/App/Startup.swift b/phpmon/Domain/App/Startup.swift
index 1511d25..bc14683 100644
--- a/phpmon/Domain/App/Startup.swift
+++ b/phpmon/Domain/App/Startup.swift
@@ -29,7 +29,7 @@ class Startup {
 
             // If we get here, something's gone wrong and the check has failed...
             Log.info("[FAIL] \(check.name)")
-            showAlert(for: check)
+            await showAlert(for: check)
             return false
         }
 
@@ -45,29 +45,27 @@ class Startup {
      - ones that require an app restart, which prompt the user to exit the app
      - ones that allow the app to continue, which allow the user to retry
      */
-    private func showAlert(for check: EnvironmentCheck) {
-        DispatchQueue.main.async {
-            if check.requiresAppRestart {
-                BetterAlert()
-                    .withInformation(
-                        title: check.titleText,
-                        subtitle: check.subtitleText,
-                        description: check.descriptionText
-                    )
-                    .withPrimary(text: check.buttonText, action: { _ in
-                        exit(1)
-                    }).show()
-            }
-
+    @MainActor private func showAlert(for check: EnvironmentCheck) {
+        if check.requiresAppRestart {
             BetterAlert()
                 .withInformation(
                     title: check.titleText,
                     subtitle: check.subtitleText,
                     description: check.descriptionText
                 )
-                .withPrimary(text: "OK")
-                .show()
+                .withPrimary(text: check.buttonText, action: { _ in
+                    exit(1)
+                }).show()
         }
+
+        BetterAlert()
+            .withInformation(
+                title: check.titleText,
+                subtitle: check.subtitleText,
+                description: check.descriptionText
+            )
+            .withPrimary(text: "OK")
+            .show()
     }
 
     /**
diff --git a/phpmon/Domain/Menu/MainMenu+Actions.swift b/phpmon/Domain/Menu/MainMenu+Actions.swift
index 8cceafd..0c62285 100644
--- a/phpmon/Domain/Menu/MainMenu+Actions.swift
+++ b/phpmon/Domain/Menu/MainMenu+Actions.swift
@@ -12,7 +12,7 @@ extension MainMenu {
 
     // MARK: - Actions
 
-    @objc func fixHomebrewPermissions() {
+    @MainActor @objc func fixHomebrewPermissions() {
         if !BetterAlert()
             .withInformation(
                 title: "alert.fix_homebrew_permissions.title".localized,
diff --git a/phpmon/Domain/Notice/BetterAlert.swift b/phpmon/Domain/Notice/BetterAlert.swift
index 4f46e28..3013415 100644
--- a/phpmon/Domain/Notice/BetterAlert.swift
+++ b/phpmon/Domain/Notice/BetterAlert.swift
@@ -31,8 +31,8 @@ class BetterAlert {
 
     public func withPrimary(
         text: String,
-        action: @escaping (BetterAlertVC) -> Void = { vc in
-            DispatchQueue.main.async { vc.close(with: .alertFirstButtonReturn) }
+        action: @MainActor @escaping (BetterAlertVC) -> Void = { vc in
+            vc.close(with: .alertFirstButtonReturn)
         }
     ) -> Self {
         self.noticeVC.buttonPrimary.title = text
@@ -42,8 +42,8 @@ class BetterAlert {
 
     public func withSecondary(
         text: String,
-        action: ((BetterAlertVC) -> Void)? = { vc in
-            DispatchQueue.main.async { vc.close(with: .alertSecondButtonReturn) }
+        action: (@MainActor (BetterAlertVC) -> Void)? = { vc in
+            vc.close(with: .alertSecondButtonReturn)
         }
     ) -> Self {
         self.noticeVC.buttonSecondary.title = text
@@ -53,7 +53,7 @@ class BetterAlert {
 
     public func withTertiary(
         text: String = "",
-        action: ((BetterAlertVC) -> Void)? = nil
+        action: (@MainActor (BetterAlertVC) -> Void)? = nil
     ) -> Self {
         if text == "" {
             self.noticeVC.buttonTertiary.bezelStyle = .helpButton
@@ -84,7 +84,7 @@ class BetterAlert {
      Shows the modal and returns a ModalResponse.
      If you wish to simply show the alert and disregard the outcome, use `show`.
      */
-    public func runModal() -> NSApplication.ModalResponse {
+    @MainActor public func runModal() -> NSApplication.ModalResponse {
         if !Thread.isMainThread {
             fatalError("You should always present alerts on the main thread!")
         }
@@ -96,7 +96,7 @@ class BetterAlert {
     }
 
     /** Shows the modal and returns true if the user pressed the primary button. */
-    public func didSelectPrimary() -> Bool {
+    @MainActor public func didSelectPrimary() -> Bool {
         return self.runModal() == .alertFirstButtonReturn
     }
 
diff --git a/phpmon/Domain/Notice/BetterAlertVC.swift b/phpmon/Domain/Notice/BetterAlertVC.swift
index eaca848..c3d58e1 100644
--- a/phpmon/Domain/Notice/BetterAlertVC.swift
+++ b/phpmon/Domain/Notice/BetterAlertVC.swift
@@ -21,9 +21,9 @@ class BetterAlertVC: NSViewController {
     @IBOutlet weak var buttonSecondary: NSButton!
     @IBOutlet weak var buttonTertiary: NSButton!
 
-    var actionPrimary: (BetterAlertVC) -> Void = { _ in }
-    var actionSecondary: ((BetterAlertVC) -> Void)?
-    var actionTertiary: ((BetterAlertVC) -> Void)?
+    var actionPrimary: (@MainActor (BetterAlertVC) -> Void) = { _ in }
+    var actionSecondary: (@MainActor (BetterAlertVC) -> Void)?
+    var actionTertiary: (@MainActor (BetterAlertVC) -> Void)?
 
     @IBOutlet weak var imageView: NSImageView!