diff --git a/cppwinrt.sln b/cppwinrt.sln
index 5964f976b..1c1a45f8a 100644
--- a/cppwinrt.sln
+++ b/cppwinrt.sln
@@ -109,8 +109,10 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "test", "test", "{3C7EA5F8-6
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "test_cpp20", "test\test_cpp20\test_cpp20.vcxproj", "{5FF6CD6C-515A-4D55-97B6-62AD9BCB77EA}"
 	ProjectSection(ProjectDependencies) = postProject
+		{559A7CF4-DC5F-4D62-BA6B-0C2B025593F8} = {559A7CF4-DC5F-4D62-BA6B-0C2B025593F8}
 		{A91B8BF3-28E4-4D9E-8DBA-64B70E4F0270} = {A91B8BF3-28E4-4D9E-8DBA-64B70E4F0270}
 		{D613FB39-5035-4043-91E2-BAB323908AF4} = {D613FB39-5035-4043-91E2-BAB323908AF4}
+		{F1C915B3-2C64-4992-AFB7-7F035B1A7607} = {F1C915B3-2C64-4992-AFB7-7F035B1A7607}
 	EndProjectSection
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "test_cpp20_no_sourcelocation", "test\test_cpp20_no_sourcelocation\test_cpp20_no_sourcelocation.vcxproj", "{D4C8F881-84D5-4A7B-8BDE-AB4E34A05374}"
diff --git a/strings/base_activation.h b/strings/base_activation.h
index be24c6ad9..5daaaf1e6 100644
--- a/strings/base_activation.h
+++ b/strings/base_activation.h
@@ -18,8 +18,11 @@ namespace winrt::impl
 
     using library_handle = handle_type<library_traits>;
 
-    template <bool isSameInterfaceAsIActivationFactory>
-    WINRT_IMPL_NOINLINE hresult get_runtime_activation_factory_impl(param::hstring const& name, winrt::guid const& guid, void** result) noexcept
+    // This function pointer will be null unless one or more translation units in a binary define WINRT_REG_FREE before
+    // including winrt/base.h.  If that is defined then the overall binary will support regfree COM activation.
+    inline hresult(*reg_free_factory_getter)(param::hstring const&, guid const&, void**) = nullptr;
+
+    WINRT_IMPL_NOINLINE inline hresult get_runtime_activation_factory_impl(param::hstring const& name, winrt::guid const& guid, void** result) noexcept
     {
         if (winrt_activation_handler)
         {
@@ -30,15 +33,8 @@ namespace winrt::impl
 
         if (hr == impl::error_not_initialized)
         {
-            auto usage = reinterpret_cast<int32_t(__stdcall*)(void** cookie) noexcept>(WINRT_IMPL_GetProcAddress(load_library(L"combase.dll"), "CoIncrementMTAUsage"));
-
-            if (!usage)
-            {
-                return hr;
-            }
-
             void* cookie;
-            usage(&cookie);
+            WINRT_IMPL_CoIncrementMTAUsage(&cookie);
             hr = WINRT_IMPL_RoGetActivationFactory(*(void**)(&name), guid, result);
         }
 
@@ -47,6 +43,21 @@ namespace winrt::impl
             return 0;
         }
 
+        // If the class is not registered, and regfree support is enabled, give that a chance to make the activation succeed.
+        // We should not attempt to fallback to regfree for error codes besides class not registered.  If the activation is out
+        // of process then we could have RPC error codes.  It would be bad if a class that should only ever be used out of proc
+        // is erroneously activated inproc.
+        if ((hr == error_class_not_registered) && reg_free_factory_getter)
+        {
+            return reg_free_factory_getter(name, guid, result);
+        }
+
+        return hr;
+    }
+
+#ifdef WINRT_REG_FREE
+    WINRT_IMPL_NOINLINE inline hresult reg_free_get_activation_factory(param::hstring const& name, winrt::guid const& guid, void** result) noexcept
+    {
         com_ptr<IErrorInfo> error_info;
         WINRT_IMPL_GetErrorInfo(0, error_info.put_void());
 
@@ -79,13 +90,7 @@ namespace winrt::impl
                 continue;
             }
 
-            if constexpr (isSameInterfaceAsIActivationFactory)
-            {
-                *result = library_factory.detach();
-                library.detach();
-                return 0;
-            }
-            else if (0 == library_factory.as(guid, result))
+            if (0 == library_factory.as(guid, result))
             {
                 library.detach();
                 return 0;
@@ -93,13 +98,31 @@ namespace winrt::impl
         }
 
         WINRT_IMPL_SetErrorInfo(0, error_info.get());
-        return hr;
+        return error_class_not_registered;
     }
 
+    // This file has been compiled by a translation unit with WINRT_REG_FREE defined.  Fill in the reg_free_factory_getter function
+    // pointer so that regfree behavior is activated.
+    inline unsigned int reg_free_init = []() {
+        reg_free_factory_getter = reg_free_get_activation_factory;
+        return 0U;
+    }();
+
+    // This pragma is used to detect if the translation unit containing regfree usage is being linked with another translation
+    // unit that declared WINRT_NEVER_REG_FREE.
+#pragma detect_mismatch("WINRT_REG_FREE", "enabled")
+#endif // WINRT_REG_FREE
+
+#ifdef WINRT_NEVER_REG_FREE
+    // This pragma is used to ensure that a binary will never have winrt regfree logic enabled.  Defining WINRT_NEVER_REG_FREE will
+    // cause this pragma to break linkage if any translation units in the same binary defined WINRT_REG_FREE.
+#pragma detect_mismatch("WINRT_REG_FREE", "never")
+#endif // WINRT_NEVER_REG_FREE
+
     template <typename Interface>
     hresult get_runtime_activation_factory(param::hstring const& name, void** result) noexcept
     {
-        return get_runtime_activation_factory_impl<std::is_same_v<Interface, Windows::Foundation::IActivationFactory>>(name, guid_of<Interface>(), result);
+        return get_runtime_activation_factory_impl(name, guid_of<Interface>(), result);
     }
 }
 
diff --git a/strings/base_agile_ref.h b/strings/base_agile_ref.h
index b85cb7e61..0dc8bfcb3 100644
--- a/strings/base_agile_ref.h
+++ b/strings/base_agile_ref.h
@@ -71,10 +71,12 @@ namespace winrt::impl
 
     using update_module_lock = module_lock_updater<true>;
 
+#ifdef WINRT_REG_FREE
     inline void* load_library(wchar_t const* library) noexcept
     {
         return WINRT_IMPL_LoadLibraryExW(library, nullptr, 0x00001000 /* LOAD_LIBRARY_SEARCH_DEFAULT_DIRS */);
     }
+#endif // WINRT_REG_FREE
 
     inline hresult get_agile_reference(winrt::guid const& iid, void* object, void** reference) noexcept
     {
diff --git a/strings/base_extern.h b/strings/base_extern.h
index 2412f9f2c..0670d8125 100644
--- a/strings/base_extern.h
+++ b/strings/base_extern.h
@@ -33,7 +33,9 @@ extern "C"
     void __stdcall WINRT_IMPL_RoFailFastWithErrorContext(int32_t) noexcept WINRT_IMPL_LINK(RoFailFastWithErrorContext, 4);
     int32_t __stdcall WINRT_IMPL_RoTransformError(int32_t, int32_t, void*) noexcept WINRT_IMPL_LINK(RoTransformError, 12);
 
+#ifdef WINRT_REG_FREE
     void* __stdcall WINRT_IMPL_LoadLibraryExW(wchar_t const* name, void* unused, uint32_t flags) noexcept WINRT_IMPL_LINK(LoadLibraryExW, 12);
+#endif // WINRT_REG_FREE
     int32_t __stdcall WINRT_IMPL_FreeLibrary(void* library) noexcept WINRT_IMPL_LINK(FreeLibrary, 4);
     void* __stdcall WINRT_IMPL_GetProcAddress(void* library, char const* name) noexcept WINRT_IMPL_LINK(GetProcAddress, 8);
 
@@ -41,6 +43,7 @@ extern "C"
     int32_t __stdcall WINRT_IMPL_GetErrorInfo(uint32_t reserved, void** info) noexcept WINRT_IMPL_LINK(GetErrorInfo, 8);
     int32_t __stdcall WINRT_IMPL_CoInitializeEx(void*, uint32_t type) noexcept WINRT_IMPL_LINK(CoInitializeEx, 8);
     void    __stdcall WINRT_IMPL_CoUninitialize() noexcept WINRT_IMPL_LINK(CoUninitialize, 0);
+    int32_t __stdcall WINRT_IMPL_CoIncrementMTAUsage(void** cookie) noexcept WINRT_IMPL_LINK(CoIncrementMTAUsage, 4);
 
     int32_t  __stdcall WINRT_IMPL_CoCreateFreeThreadedMarshaler(void* outer, void** marshaler) noexcept WINRT_IMPL_LINK(CoCreateFreeThreadedMarshaler, 8);
     int32_t  __stdcall WINRT_IMPL_CoCreateInstance(winrt::guid const& clsid, void* outer, uint32_t context, winrt::guid const& iid, void** object) noexcept WINRT_IMPL_LINK(CoCreateInstance, 20);
diff --git a/test/old_tests/UnitTests/pch.h b/test/old_tests/UnitTests/pch.h
index 4b940b552..6b146a3bc 100644
--- a/test/old_tests/UnitTests/pch.h
+++ b/test/old_tests/UnitTests/pch.h
@@ -1,6 +1,7 @@
 #pragma once
 
-#define WIN32_LEAN_AND_MEAN 
+#define WIN32_LEAN_AND_MEAN
+#define WINRT_REG_FREE
 #define WINRT_NATVIS
 #define _SILENCE_CXX17_UNCAUGHT_EXCEPTION_DEPRECATION_WARNING
 
diff --git a/test/test/pch.h b/test/test/pch.h
index 24d65c225..b2392e14a 100644
--- a/test/test/pch.h
+++ b/test/test/pch.h
@@ -5,6 +5,7 @@
 #include "mingw_com_support.h"
 
 #define WINRT_LEAN_AND_MEAN
+#define WINRT_REG_FREE
 #include <unknwn.h>
 #include "winrt/Windows.Foundation.Collections.h"
 #include "winrt/Windows.Foundation.Numerics.h"
diff --git a/test/test_cpp20/activation_without_regfree.cpp b/test/test_cpp20/activation_without_regfree.cpp
new file mode 100644
index 000000000..b54a3471e
--- /dev/null
+++ b/test/test_cpp20/activation_without_regfree.cpp
@@ -0,0 +1,43 @@
+#include "pch.h"
+#include "winrt/test_component.h"
+
+using namespace winrt;
+using namespace Windows::Foundation;
+using namespace test_component;
+
+TEST_CASE("activation_withoug_regfree_system_type")
+{
+    REQUIRE_NOTHROW(Uri(L"https://bing.com"));
+}
+
+TEST_CASE("activation_manifested_avoiding_regfree")
+{
+    bool fusionRegistrationWorked{ false };
+    try
+    {
+        // app.manifest has registration for the Simple runtimeclass so activation should succeed.
+        Simple s{};
+        fusionRegistrationWorked = true;
+    }
+    catch (...)
+    {
+    }
+    REQUIRE(fusionRegistrationWorked);
+}
+
+TEST_CASE("activation_withoug_regfree_fails")
+{
+    bool threwException{ false };
+    try
+    {
+        Class c;
+        REQUIRE(false);
+    }
+    catch (winrt::hresult_class_not_registered& e)
+    {
+        threwException = true;
+        REQUIRE(e.code() == winrt::impl::error_class_not_registered);
+    }
+
+    REQUIRE(threwException);
+}
\ No newline at end of file
diff --git a/test/test_cpp20/app.manifest b/test/test_cpp20/app.manifest
new file mode 100644
index 000000000..c88b6cffa
--- /dev/null
+++ b/test/test_cpp20/app.manifest
@@ -0,0 +1,9 @@
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
+    <file name="test_component.dll">
+        <activatableClass
+            name="test_component.Simple"
+            threadingModel="both"
+            xmlns="urn:schemas-microsoft-com:winrt.v1"
+         />
+    </file>
+</assembly>
\ No newline at end of file
diff --git a/test/test_cpp20/pch.h b/test/test_cpp20/pch.h
index c1a8f5ff3..dffca9d27 100644
--- a/test/test_cpp20/pch.h
+++ b/test/test_cpp20/pch.h
@@ -3,6 +3,7 @@
 #pragma warning(4: 4458) // ensure we compile clean with this warning enabled
 
 #define WINRT_LEAN_AND_MEAN
+#define WINRT_NEVER_REG_FREE
 #include <unknwn.h>
 #include "winrt/Windows.Data.Json.h"
 #include "winrt/Windows.Foundation.h"
diff --git a/test/test_cpp20/test_cpp20.vcxproj b/test/test_cpp20/test_cpp20.vcxproj
index 832297f7f..fdbbd7f65 100644
--- a/test/test_cpp20/test_cpp20.vcxproj
+++ b/test/test_cpp20/test_cpp20.vcxproj
@@ -100,8 +100,7 @@
       <OptimizeReferences>true</OptimizeReferences>
     </Link>
     <PreBuildEvent>
-      <Command>
-      </Command>
+      <Command>$(CppWinRTDir)cppwinrt -in $(OutputPath)test_component.winmd $(OutputPath)test_component_no_pch.winmd -out "$(ProjectDir)Generated Files" -ref sdk -verbose -fastabi</Command>
     </PreBuildEvent>
     <PostBuildEvent>
       <Command>
@@ -119,8 +118,7 @@
       <SubSystem>Console</SubSystem>
     </Link>
     <PreBuildEvent>
-      <Command>
-      </Command>
+      <Command>$(CppWinRTDir)cppwinrt -in $(OutputPath)test_component.winmd $(OutputPath)test_component_no_pch.winmd -out "$(ProjectDir)Generated Files" -ref sdk -verbose -fastabi</Command>
     </PreBuildEvent>
     <PostBuildEvent>
       <Command>
@@ -138,8 +136,7 @@
       <SubSystem>Console</SubSystem>
     </Link>
     <PreBuildEvent>
-      <Command>
-      </Command>
+      <Command>$(CppWinRTDir)cppwinrt -in $(OutputPath)test_component.winmd $(OutputPath)test_component_no_pch.winmd -out "$(ProjectDir)Generated Files" -ref sdk -verbose -fastabi</Command>
     </PreBuildEvent>
     <PostBuildEvent>
       <Command>
@@ -157,8 +154,7 @@
       <SubSystem>Console</SubSystem>
     </Link>
     <PreBuildEvent>
-      <Command>
-      </Command>
+      <Command>$(CppWinRTDir)cppwinrt -in $(OutputPath)test_component.winmd $(OutputPath)test_component_no_pch.winmd -out "$(ProjectDir)Generated Files" -ref sdk -verbose -fastabi</Command>
     </PreBuildEvent>
     <PostBuildEvent>
       <Command>
@@ -180,8 +176,7 @@
       <OptimizeReferences>true</OptimizeReferences>
     </Link>
     <PreBuildEvent>
-      <Command>
-      </Command>
+      <Command>$(CppWinRTDir)cppwinrt -in $(OutputPath)test_component.winmd $(OutputPath)test_component_no_pch.winmd -out "$(ProjectDir)Generated Files" -ref sdk -verbose -fastabi</Command>
     </PreBuildEvent>
     <PostBuildEvent>
       <Command>
@@ -203,8 +198,7 @@
       <OptimizeReferences>true</OptimizeReferences>
     </Link>
     <PreBuildEvent>
-      <Command>
-      </Command>
+      <Command>$(CppWinRTDir)cppwinrt -in $(OutputPath)test_component.winmd $(OutputPath)test_component_no_pch.winmd -out "$(ProjectDir)Generated Files" -ref sdk -verbose -fastabi</Command>
     </PreBuildEvent>
     <PostBuildEvent>
       <Command>
@@ -215,6 +209,7 @@
     <ClInclude Include="pch.h" />
   </ItemGroup>
   <ItemGroup>
+    <ClCompile Include="activation_without_regfree.cpp" />
     <ClCompile Include="array_span.cpp" />
     <ClCompile Include="await_completed.cpp" />
     <ClCompile Include="custom_error.cpp" />
@@ -228,6 +223,9 @@
     </ClCompile>
     <ClCompile Include="ranges.cpp" />
   </ItemGroup>
+  <ItemGroup>
+    <Manifest Include="app.manifest" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
diff --git a/test/test_fast/pch.h b/test/test_fast/pch.h
index 97769b358..11dbff990 100644
--- a/test/test_fast/pch.h
+++ b/test/test_fast/pch.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#define WINRT_REG_FREE
 #include "catch.hpp"
 #include "winrt/Windows.Foundation.Collections.h"
 
diff --git a/test/test_slow/pch.h b/test/test_slow/pch.h
index 97769b358..11dbff990 100644
--- a/test/test_slow/pch.h
+++ b/test/test_slow/pch.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#define WINRT_REG_FREE
 #include "catch.hpp"
 #include "winrt/Windows.Foundation.Collections.h"