diff --git a/src/CalcManager/CalcManager.vcxproj b/src/CalcManager/CalcManager.vcxproj
index 4a098141..f2d46f36 100644
--- a/src/CalcManager/CalcManager.vcxproj
+++ b/src/CalcManager/CalcManager.vcxproj
@@ -303,6 +303,10 @@
     <ClInclude Include="Ratpack\ratconst.h" />
     <ClInclude Include="Ratpack\ratpak.h" />
     <ClInclude Include="UnitConverter.h" />
+    <ClInclude Include="preprocessor_cross_platform.h" />
+    <ClInclude Include="sal_cross_platform.h" />
+    <ClInclude Include="win_data_types_cross_platform.h" />
+    <ClInclude Include="winerror_cross_platform.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="CalculatorHistory.cpp" />
@@ -346,4 +350,4 @@
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets" />
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/CalcManager/CalcManager.vcxproj.filters b/src/CalcManager/CalcManager.vcxproj.filters
index 2ca11666..b96ee3d4 100644
--- a/src/CalcManager/CalcManager.vcxproj.filters
+++ b/src/CalcManager/CalcManager.vcxproj.filters
@@ -160,5 +160,9 @@
     <ClInclude Include="Header Files\RationalMath.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="preprocessor_cross_platform.h" />
+    <ClInclude Include="sal_cross_platform.h" />
+    <ClInclude Include="win_data_types_cross_platform.h" />
+    <ClInclude Include="winerror_cross_platform.h" />
   </ItemGroup>
 </Project>