diff --git a/src/Main/Base/Project/ICSharpCode.SharpDevelop.csproj b/src/Main/Base/Project/ICSharpCode.SharpDevelop.csproj
index 312939469f..0b6b7a4da5 100644
--- a/src/Main/Base/Project/ICSharpCode.SharpDevelop.csproj
+++ b/src/Main/Base/Project/ICSharpCode.SharpDevelop.csproj
@@ -729,6 +729,7 @@
     <Compile Include="Src\TextEditor\Gui\Editor\CompletionWindow\OverrideCompletionDataProvider.cs" />
     <Compile Include="Src\Gui\Pads\TaskList\TaskView.cs" />
     <Compile Include="Src\Gui\Pads\TaskList\TaskListPad.cs" />
+    <Compile Include="Src\Internal\Undo\MSBuildFile.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\..\Libraries\DockPanel_Src\WinFormsUI\WinFormsUI.csproj">