diff --git a/src/cascadia/WinRTUtils/WinRTUtils.vcxproj b/src/cascadia/WinRTUtils/WinRTUtils.vcxproj
index 2bd60e143..ee25e2a3f 100644
--- a/src/cascadia/WinRTUtils/WinRTUtils.vcxproj
+++ b/src/cascadia/WinRTUtils/WinRTUtils.vcxproj
@@ -15,8 +15,9 @@
   <!-- ========================= Headers ======================== -->
   <ItemGroup>
     <ClInclude Include="pch.h" />
-    <ClInclude Include="inc\ScopedResourceLoader.h" />
     <ClInclude Include="inc\LibraryResources.h" />
+    <ClInclude Include="inc\ScopedResourceLoader.h" />
+    <ClInclude Include="inc\thread_assert.h" />
     <ClInclude Include="inc\ThrottledFunc.h" />
     <ClInclude Include="inc\Utils.h" />
     <ClInclude Include="inc\WtExeUtils.h" />
@@ -28,6 +29,7 @@
     </ClCompile>
     <ClCompile Include="LibraryResources.cpp" />
     <ClCompile Include="ScopedResourceLoader.cpp" />
+    <ClCompile Include="thread_assert.cpp" />
   </ItemGroup>
   <!-- ========================= idl Files ======================== -->
   <ItemGroup>
diff --git a/src/cascadia/WinRTUtils/WinRTUtils.vcxproj.filters b/src/cascadia/WinRTUtils/WinRTUtils.vcxproj.filters
index edaac5a3d..6b69e2359 100644
--- a/src/cascadia/WinRTUtils/WinRTUtils.vcxproj.filters
+++ b/src/cascadia/WinRTUtils/WinRTUtils.vcxproj.filters
@@ -7,11 +7,13 @@
     <ClCompile Include="pch.cpp" />
     <ClCompile Include="LibraryResources.cpp" />
     <ClCompile Include="ScopedResourceLoader.cpp" />
+    <ClCompile Include="thread_assert.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="pch.h" />
-    <ClInclude Include="ScopedResourceLoader.h" />
     <ClInclude Include="inc\LibraryResources.h" />
+    <ClInclude Include="inc\ScopedResourceLoader.h" />
+    <ClInclude Include="inc\thread_assert.h" />
     <ClInclude Include="inc\ThrottledFunc.h" />
     <ClInclude Include="inc\Utils.h" />
     <ClInclude Include="inc\WtExeUtils.h" />
diff --git a/src/cascadia/WinRTUtils/inc/thread_assert.h b/src/cascadia/WinRTUtils/inc/thread_assert.h
new file mode 100644
index 000000000..ebec4facc
--- /dev/null
+++ b/src/cascadia/WinRTUtils/inc/thread_assert.h
@@ -0,0 +1,14 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#pragma once
+
+#ifdef NDEBUG
+constexpr void mark_as_foreground_thread() {}
+constexpr void assert_foreground_thread() {}
+constexpr void assert_background_thread() {}
+#else
+void mark_as_foreground_thread();
+void assert_foreground_thread();
+void assert_background_thread();
+#endif
diff --git a/src/cascadia/WinRTUtils/thread_assert.cpp b/src/cascadia/WinRTUtils/thread_assert.cpp
new file mode 100644
index 000000000..d1b2c9a99
--- /dev/null
+++ b/src/cascadia/WinRTUtils/thread_assert.cpp
@@ -0,0 +1,27 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "pch.h"
+#include "thread_assert.h"
+
+#ifndef NDEBUG
+
+static const DWORD foreground_thread_id = []() -> DWORD {
+    const auto id = GetCurrentThreadId();
+    OutputDebugStringW((std::wstring(L"#### ") + std::to_wstring(id) + L" ####").c_str());
+    return id;
+}();
+
+void assert_foreground_thread() {
+    if (foreground_thread_id != GetCurrentThreadId()) {
+        //throw std::exception("expected to be called from a foreground thread");
+    }
+}
+
+void assert_background_thread() {
+    if (foreground_thread_id != GetCurrentThreadId()) {
+        throw std::exception("expected to be called from a background thread");
+    }
+}
+
+#endif // NDEBUG