--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -71,6 +71,10 @@
       <AdditionalOptions>/Zm200  %(AdditionalOptions)</AdditionalOptions>
       <AdditionalIncludeDirectories>$(PySourcePath)Python;$(PySourcePath)Modules\zlib;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>_USRDLL;Py_BUILD_CORE;Py_NO_ENABLE_SHARED;MS_DLL_ID="$(SysWinVer)";%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <RuntimeLibrary Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">MultiThreadedDebug</RuntimeLibrary>
+      <RuntimeLibrary Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">MultiThreadedDebug</RuntimeLibrary>
+      <RuntimeLibrary Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">MultiThreaded</RuntimeLibrary>
+      <RuntimeLibrary Condition="'$(Configuration)|$(Platform)'=='Release|x64'">MultiThreaded</RuntimeLibrary>
     </ClCompile>
     <Link>
       <AdditionalDependencies>ws2_32.lib;%(AdditionalDependencies)</AdditionalDependencies>
--