diff --git a/include/grpc/support/port_platform.h b/include/grpc/support/port_platform.h
index 93291a174da..e5d45590aec 100644
--- a/include/grpc/support/port_platform.h
+++ b/include/grpc/support/port_platform.h
@@ -46,10 +46,11 @@
 #define NOMINMAX
 #endif /* NOMINMAX */
 
-#if defined(_WIN32_WINNT)
-#if _WIN32_WINNT < 0x0600
-#undef _WIN32_WINNT
-#define _WIN32_WINNT 0x0600
+#ifndef _WIN32_WINNT
+#error "Please compile grpc with _WIN32_WINNT of at least 0x600 (aka Windows Vista)"
+#else /* !defined(_WIN32_WINNT) */
+#if (_WIN32_WINNT < 0x0600)
+#error "Please compile grpc with _WIN32_WINNT of at least 0x600 (aka Windows Vista)"
 #endif /* _WIN32_WINNT < 0x0600 */
 #endif /* defined(_WIN32_WINNT) */
 
diff --git a/templates/vsprojects/global.props.template b/templates/vsprojects/global.props.template
index 0fc86c45463..5b8d1e1182a 100644
--- a/templates/vsprojects/global.props.template
+++ b/templates/vsprojects/global.props.template
@@ -10,7 +10,7 @@
     <ItemDefinitionGroup>
       <ClCompile>
         <AdditionalIncludeDirectories>$(SolutionDir)\..;$(SolutionDir)\..\include;$(SolutionDir)\..\third_party\protobuf\src;${';'.join('$(SolutionDir)\\packages\\%s.%s\\build\\native\\include' % (p.name, p.version) for p in vspackages)};%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-        <PreprocessorDefinitions>_SCL_SECURE_NO_WARNINGS;_CRT_SECURE_NO_WARNINGS;_UNICODE;UNICODE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+        <PreprocessorDefinitions>_WIN32_WINNT=0x600;_SCL_SECURE_NO_WARNINGS;_CRT_SECURE_NO_WARNINGS;_UNICODE;UNICODE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
         <WarningLevel>EnableAllWarnings</WarningLevel>
       </ClCompile>
     </ItemDefinitionGroup>
diff --git a/vsprojects/global.props b/vsprojects/global.props
index 3ee06ac849f..8786497ef33 100644
--- a/vsprojects/global.props
+++ b/vsprojects/global.props
@@ -8,7 +8,7 @@
   <ItemDefinitionGroup>
     <ClCompile>
       <AdditionalIncludeDirectories>$(SolutionDir)\..;$(SolutionDir)\..\include;$(SolutionDir)\..\third_party\protobuf\src;$(SolutionDir)\packages\grpc.dependencies.zlib.1.2.8.9\build\native\include;$(SolutionDir)\packages\grpc.dependencies.openssl.1.0.2.3\build\native\include;$(SolutionDir)\packages\gflags.2.1.2.1\build\native\include;$(SolutionDir)\packages\gtest.1.7.0.1\build\native\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_SCL_SECURE_NO_WARNINGS;_CRT_SECURE_NO_WARNINGS;_UNICODE;UNICODE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_WIN32_WINNT=0x600;_SCL_SECURE_NO_WARNINGS;_CRT_SECURE_NO_WARNINGS;_UNICODE;UNICODE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <WarningLevel>EnableAllWarnings</WarningLevel>
     </ClCompile>
   </ItemDefinitionGroup>