diff --git a/PCbuild/_bz2.vcxproj b/PCbuild/_bz2.vcxproj
index 9efb0d9a792..65da7a4c31f 100644
--- a/PCbuild/_bz2.vcxproj
+++ b/PCbuild/_bz2.vcxproj
@@ -64,6 +64,7 @@
     <ClCompile>
       <AdditionalIncludeDirectories>$(bz2Dir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>WIN32;_FILE_OFFSET_BITS=64;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_DEPRECATE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+	  <DisableSpecificWarnings>4244;4267;%(DisableSpecificWarnings)</DisableSpecificWarnings>
     </ClCompile>
     <Link>
       <BaseAddress>0x1D170000</BaseAddress>
diff --git a/PCbuild/liblzma.vcxproj b/PCbuild/liblzma.vcxproj
index 0934cc558c7..f408b547855 100644
--- a/PCbuild/liblzma.vcxproj
+++ b/PCbuild/liblzma.vcxproj
@@ -64,7 +64,7 @@
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>$(lzmaDir)windows;$(lzmaDir)src/liblzma/common;$(lzmaDir)src/common;$(lzmaDir)src/liblzma/api;$(lzmaDir)src/liblzma/check;$(lzmaDir)src/liblzma/delta;$(lzmaDir)src/liblzma/lz;$(lzmaDir)src/liblzma/lzma;$(lzmaDir)src/liblzma/rangecoder;$(lzmaDir)src/liblzma/simple</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4028;4113;4133;4244;4267;4996</DisableSpecificWarnings>
+      <DisableSpecificWarnings>4028;4113;4133;4244;4267;4996;%(DisableSpecificWarnings)</DisableSpecificWarnings>
     </ClCompile>
   </ItemDefinitionGroup>
   <ItemGroup>