diff --git a/src/windows/libespeak-ng.vcxproj b/src/windows/libespeak-ng.vcxproj
index 0ede06b4..d780e705 100644
--- a/src/windows/libespeak-ng.vcxproj
+++ b/src/windows/libespeak-ng.vcxproj
@@ -88,7 +88,7 @@
       <WarningLevel>Level3</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>$(ProjectDir);$(ProjectDir)/../include;$(ProjectDir)/../include/compat</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>LIBESPEAK_NG_EXPORT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>LIBESPEAK_NG_EXPORT;INCLUDE_KLATT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ProgramDataBaseFileName>$(IntDir)libespeak-ng.pdb</ProgramDataBaseFileName>
     </ClCompile>
     <Link>
@@ -102,7 +102,7 @@
       </PrecompiledHeader>
       <WarningLevel>Level3</WarningLevel>
       <Optimization>Disabled</Optimization>
-      <PreprocessorDefinitions>LIBESPEAK_NG_EXPORT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>LIBESPEAK_NG_EXPORT;INCLUDE_KLATT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ProgramDataBaseFileName>$(IntDir)libespeak-ng.pdb</ProgramDataBaseFileName>
     </ClCompile>
     <Link>
@@ -119,7 +119,7 @@
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>$(ProjectDir);$(ProjectDir)/../include;$(ProjectDir)/../include/compat</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>LIBESPEAK_NG_EXPORT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>LIBESPEAK_NG_EXPORT;INCLUDE_KLATT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ProgramDataBaseFileName>$(IntDir)libespeak-ng.pdb</ProgramDataBaseFileName>
     </ClCompile>
     <Link>
@@ -137,7 +137,7 @@
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
-      <PreprocessorDefinitions>LIBESPEAK_NG_EXPORT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>LIBESPEAK_NG_EXPORT;INCLUDE_KLATT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ProgramDataBaseFileName>$(IntDir)libespeak-ng.pdb</ProgramDataBaseFileName>
     </ClCompile>
     <Link>
@@ -156,6 +156,7 @@
     <ClCompile Include="..\libespeak-ng\espeak_api.c" />
     <ClCompile Include="..\libespeak-ng\ieee80.c" />
     <ClCompile Include="..\libespeak-ng\intonation.c" />
+    <ClCompile Include="..\libespeak-ng\klatt.c" />
     <ClCompile Include="..\libespeak-ng\numbers.c" />
     <ClCompile Include="..\libespeak-ng\phonemelist.c" />
     <ClCompile Include="..\libespeak-ng\readclause.c" />
@@ -174,6 +175,7 @@
     <ClInclude Include="..\include\espeak-ng\espeak_ng.h" />
     <ClInclude Include="..\include\espeak\speak_lib.h" />
     <ClInclude Include="..\libespeak-ng\error.h" />
+    <ClInclude Include="..\libespeak-ng\klatt.h" />
     <ClInclude Include="..\libespeak-ng\phoneme.h" />
     <ClInclude Include="..\libespeak-ng\sintab.h" />
     <ClInclude Include="..\libespeak-ng\spect.h" />
diff --git a/src/windows/libespeak-ng.vcxproj.filters b/src/windows/libespeak-ng.vcxproj.filters
index a0fce69c..994fb6e4 100644
--- a/src/windows/libespeak-ng.vcxproj.filters
+++ b/src/windows/libespeak-ng.vcxproj.filters
@@ -81,6 +81,9 @@
     <ClCompile Include="..\libespeak-ng\wavegen.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\libespeak-ng\klatt.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="config.h">
@@ -116,5 +119,8 @@
     <ClInclude Include="..\libespeak-ng\voice.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\libespeak-ng\klatt.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file