diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5e2677fed..731c6a4a7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -45,7 +45,7 @@ jobs:
           $target_configuration = "${{ matrix.config }}"
           $target_platform = "${{ matrix.arch }}"
           $target_version = "999.999.999.999"
-          $props = "Configuration=$target_configuration,Platform=$target_platform,CppWinRTBuildVersion=$target_version"
+          $props = "Configuration=$target_configuration,Platform=$target_platform,CppWinRTBuildVersion=$target_version,CppWinRTEnableAllWarnings=true"
           if ("${{ matrix.compiler }}" -eq "clang-cl") {
             $props += ",Clang=1,PlatformToolset=ClangCl"
           } else {
@@ -146,7 +146,7 @@ jobs:
           $target_configuration = "${{ matrix.config }}"
           $target_platform = "${{ matrix.arch }}"
           $target_version = "999.999.999.999"
-          $props = "Configuration=$target_configuration,Platform=$target_platform,CppWinRTBuildVersion=$target_version"
+          $props = "Configuration=$target_configuration,Platform=$target_platform,CppWinRTBuildVersion=$target_version,CppWinRTEnableAllWarnings=true"
           if ("${{ matrix.compiler }}" -eq "clang-cl") {
             $props += ",Clang=1,PlatformToolset=ClangCl"
           } else {
@@ -315,7 +315,7 @@ jobs:
           $target_configuration = "${{ matrix.config }}"
           $target_platform = "${{ matrix.arch }}"
           $target_version = "999.999.999.999"
-          Add-Content $env:GITHUB_ENV "msbuild_config_props=/p:Configuration=$target_configuration,Platform=$target_platform,CppWinRTBuildVersion=$target_version,PlatformToolset=v145"
+          Add-Content $env:GITHUB_ENV "msbuild_config_props=/p:Configuration=$target_configuration,Platform=$target_platform,CppWinRTBuildVersion=$target_version,CppWinRTEnableAllWarnings=true,PlatformToolset=v145"
 
       - name: Restore nuget packages
         run: |
@@ -364,7 +364,7 @@ jobs:
           $target_configuration = "${{ matrix.config }}"
           $target_platform = "${{ matrix.arch }}"
           $target_version = "999.999.999.999"
-          Add-Content $env:GITHUB_ENV "msbuild_config_props=/p:Configuration=$target_configuration,Platform=$target_platform,CppWinRTBuildVersion=$target_version,PlatformToolset=${{ matrix.toolchain.platform_toolset }}"
+          Add-Content $env:GITHUB_ENV "msbuild_config_props=/p:Configuration=$target_configuration,Platform=$target_platform,CppWinRTBuildVersion=$target_version,CppWinRTEnableAllWarnings=true,PlatformToolset=${{ matrix.toolchain.platform_toolset }}"
 
       - name: Restore nuget packages
         run: |
diff --git a/Directory.Build.targets b/Directory.Build.targets
new file mode 100644
index 000000000..a7de1e4e1
--- /dev/null
+++ b/Directory.Build.targets
@@ -0,0 +1,10 @@
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <ItemDefinitionGroup Condition="'$(CppWinRTEnableAllWarnings)'=='true'">
+    <ClCompile>
+      <WarningLevel>EnableAllWarnings</WarningLevel>
+      <TreatWarningAsError>false</TreatWarningAsError>
+    </ClCompile>
+  </ItemDefinitionGroup>
+
+</Project>
diff --git a/cppwinrt/cppwinrt.vcxproj b/cppwinrt/cppwinrt.vcxproj
index 3efa7a64c..1aeafd0d9 100644
--- a/cppwinrt/cppwinrt.vcxproj
+++ b/cppwinrt/cppwinrt.vcxproj
@@ -176,7 +176,7 @@
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\inc;$(OutputPath);$(WinMDPackageDir);</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>EnableAllWarnings</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
     <Link>
@@ -195,7 +195,7 @@
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\inc;$(OutputPath);$(WinMDPackageDir);</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>EnableAllWarnings</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
     <Link>
@@ -214,7 +214,7 @@
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\inc;$(OutputPath);$(WinMDPackageDir);</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>EnableAllWarnings</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
     <Link>
@@ -236,7 +236,7 @@
       <AdditionalIncludeDirectories>..\inc;$(OutputPath);$(WinMDPackageDir);</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <ControlFlowGuard>Guard</ControlFlowGuard>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>EnableAllWarnings</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
     <Link>
@@ -261,7 +261,7 @@
       <AdditionalIncludeDirectories>..\inc;$(OutputPath);$(WinMDPackageDir);</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <ControlFlowGuard>Guard</ControlFlowGuard>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>EnableAllWarnings</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
     <Link>
@@ -286,7 +286,7 @@
       <AdditionalIncludeDirectories>..\inc;$(OutputPath);$(WinMDPackageDir);</AdditionalIncludeDirectories>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <ControlFlowGuard>Guard</ControlFlowGuard>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>EnableAllWarnings</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
     </ClCompile>
     <Link>