diff --git a/build-windows/pEpEngine.vcxproj b/build-windows/pEpEngine.vcxproj
index 080c884d..eb10ca55 100644
--- a/build-windows/pEpEngine.vcxproj
+++ b/build-windows/pEpEngine.vcxproj
@@ -139,6 +139,7 @@
     <ClCompile Include="..\src\etpan_mime.c" />
     <ClCompile Include="..\src\growing_buf.c" />
     <ClCompile Include="..\src\identity_list.c" />
+    <ClCompile Include="..\src\internal_format.c" />
     <ClCompile Include="..\src\keymanagement.c" />
     <ClCompile Include="..\src\keyreset_command.c" />
     <ClCompile Include="..\src\KeySync_fsm.c" />
@@ -180,6 +181,7 @@
     <ClInclude Include="..\src\fsm_common.h" />
     <ClInclude Include="..\src\growing_buf.h" />
     <ClInclude Include="..\src\identity_list.h" />
+    <ClInclude Include="..\src\internal_format.h" />
     <ClInclude Include="..\src\keymanagement.h" />
     <ClInclude Include="..\src\KeySync_fsm.h" />
     <ClInclude Include="..\src\key_reset.h" />
diff --git a/build-windows/pEpEngine.vcxproj.filters b/build-windows/pEpEngine.vcxproj.filters
index 66a2b3c4..b482a431 100644
--- a/build-windows/pEpEngine.vcxproj.filters
+++ b/build-windows/pEpEngine.vcxproj.filters
@@ -126,6 +126,9 @@
     <ClCompile Include="..\src\distribution_codec.c">
       <Filter>Quelldateien</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\internal_format.c">
+      <Filter>Quelldateien</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\src\keymanagement.h">
@@ -266,6 +269,9 @@
     <ClInclude Include="..\src\sync_codec.h">
       <Filter>Headerdateien</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\internal_format.h">
+      <Filter>Headerdateien</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Text Include="..\LICENSE.txt" />