diff --git a/test/inc/TestDef.h b/test/inc/TestDef.h
index 7ca711c876..aa97f75ff7 100644
--- a/test/inc/TestDef.h
+++ b/test/inc/TestDef.h
@@ -1,7 +1,11 @@
-// Copyright (c) Microsoft Corporation and Contributors.
+// Copyright (c) Microsoft Corporation and Contributors.
 // Licensed under the MIT License.
 #pragma once
 
+#include <windows.h>
+#include <string>
+#include <winrt/base.h>
+
 constexpr static const int c_phaseTimeout = (30 * 1000); // 30 seconds
 static const std::wstring c_genericTestMoniker = L"this_is_a_test";
 static const std::wstring c_testFailureEventName = L"WindowsAppRuntimeTestFailureEventName";
diff --git a/test/inc/WindowsAppRuntime.Test.AppModel.h b/test/inc/WindowsAppRuntime.Test.AppModel.h
index 5a025ed8a4..da628fe7e5 100644
--- a/test/inc/WindowsAppRuntime.Test.AppModel.h
+++ b/test/inc/WindowsAppRuntime.Test.AppModel.h
@@ -1,11 +1,11 @@
-// Copyright (c) Microsoft Corporation and Contributors.
+// Copyright (c) Microsoft Corporation and Contributors.
 // Licensed under the MIT License.
 
 #ifndef __WINDOWSAPPRUNTIME_TEST_APPMODEL_H
 #define __WINDOWSAPPRUNTIME_TEST_APPMODEL_H
 
+#include <windows.h>
 #include <appmodel.h>
-
 #include <Verify.h>
 
 namespace Test::AppModel
diff --git a/test/inc/WindowsAppRuntime.Test.Bootstrap.h b/test/inc/WindowsAppRuntime.Test.Bootstrap.h
index a831f77aa0..10fa5ee95a 100644
--- a/test/inc/WindowsAppRuntime.Test.Bootstrap.h
+++ b/test/inc/WindowsAppRuntime.Test.Bootstrap.h
@@ -4,6 +4,7 @@
 #ifndef __WINDOWSAPPRUNTIME_TEST_BOOTSTRAP_H
 #define __WINDOWSAPPRUNTIME_TEST_BOOTSTRAP_H
 
+#include <windows.h>
 #include <MddBootstrap.h>
 #include <MddBootstrapTest.h>
 
diff --git a/test/inc/WindowsAppRuntime.Test.FileSystem.h b/test/inc/WindowsAppRuntime.Test.FileSystem.h
index b8b5235942..f17b81c360 100644
--- a/test/inc/WindowsAppRuntime.Test.FileSystem.h
+++ b/test/inc/WindowsAppRuntime.Test.FileSystem.h
@@ -1,10 +1,12 @@
-// Copyright (c) Microsoft Corporation and Contributors.
+// Copyright (c) Microsoft Corporation and Contributors.
 // Licensed under the MIT License.
 
 #ifndef __WINDOWSAPPRUNTIME_TEST_FILESYSTEM_H
 #define __WINDOWSAPPRUNTIME_TEST_FILESYSTEM_H
 
+#include <windows.h>
 #include <filesystem>
+#include <verify.h>
 
 #include <wil/win32_helpers.h>
 #include <wil/resource.h>
diff --git a/test/inc/WindowsAppRuntime.Test.Package.h b/test/inc/WindowsAppRuntime.Test.Package.h
index d8a6d319e0..4824fb4f56 100644
--- a/test/inc/WindowsAppRuntime.Test.Package.h
+++ b/test/inc/WindowsAppRuntime.Test.Package.h
@@ -4,6 +4,7 @@
 #ifndef __WINDOWSAPPRUNTIME_TEST_PACKAGE_H
 #define __WINDOWSAPPRUNTIME_TEST_PACKAGE_H
 
+#include <windows.h>
 #include <appmodel.h>
 
 #include <WindowsAppRuntime.Test.FileSystem.h>
diff --git a/test/inc/WindowsAppRuntime.Test.TAEF.cppwinrt.h b/test/inc/WindowsAppRuntime.Test.TAEF.cppwinrt.h
index 2662a1eb27..83f8e3b4c0 100644
--- a/test/inc/WindowsAppRuntime.Test.TAEF.cppwinrt.h
+++ b/test/inc/WindowsAppRuntime.Test.TAEF.cppwinrt.h
@@ -1,9 +1,13 @@
-// Copyright (c) Microsoft Corporation and Contributors. All rights reserved.
+// Copyright (c) Microsoft Corporation and Contributors. All rights reserved.
 // Licensed under the MIT License.
 
 #ifndef __WINDOWSAPPRUNTIME_TEST_TAEF_CPPWINRT_H
 #define __WINDOWSAPPRUNTIME_TEST_TAEF_CPPWINRT_H
 
+#include <windows.h>
+#include <winrt/base.h>
+#include <WexTestClass.h>
+
 namespace WEX::TestExecution
 {
     // Teach TAEF how to format a winrt::hstring
diff --git a/test/inc/WindowsAppRuntime.Test.TAEF.h b/test/inc/WindowsAppRuntime.Test.TAEF.h
index 4934bffaa0..d10d646240 100644
--- a/test/inc/WindowsAppRuntime.Test.TAEF.h
+++ b/test/inc/WindowsAppRuntime.Test.TAEF.h
@@ -1,9 +1,13 @@
-// Copyright (c) Microsoft Corporation and Contributors. All rights reserved.
+// Copyright (c) Microsoft Corporation and Contributors. All rights reserved.
 // Licensed under the MIT License.
 
 #ifndef __WINDOWSAPPRUNTIME_TEST_TAEF_H
 #define __WINDOWSAPPRUNTIME_TEST_TAEF_H
 
+#include <windows.h>
+#include <filesystem>
+#include <WexTestClass.h>
+
 namespace Test::TAEF
 {
     inline std::filesystem::path GetDeploymentDir()