diff --git a/Deckungsbeitrag.csproj b/Deckungsbeitrag.csproj
index dc61643..3154419 100644
--- a/Deckungsbeitrag.csproj
+++ b/Deckungsbeitrag.csproj
@@ -482,6 +482,9 @@
       <Install>false</Install>
     </BootstrapperPackage>
   </ItemGroup>
+  <ItemGroup>
+    <Folder Include="Old-Forms\" />
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Import Project="packages\Microsoft.Extensions.Logging.Abstractions.6.0.0\build\Microsoft.Extensions.Logging.Abstractions.targets" Condition="Exists('packages\Microsoft.Extensions.Logging.Abstractions.6.0.0\build\Microsoft.Extensions.Logging.Abstractions.targets')" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">