diff --git a/src/Shared/HandyControl_Shared/Controls/Attach/ListBoxAttach.cs b/src/Shared/HandyControl_Shared/Controls/Attach/ListBoxAttach.cs
index a7496950..fcc323a0 100644
--- a/src/Shared/HandyControl_Shared/Controls/Attach/ListBoxAttach.cs
+++ b/src/Shared/HandyControl_Shared/Controls/Attach/ListBoxAttach.cs
@@ -6,7 +6,7 @@
 
 namespace HandyControl.Controls;
 
-public class ListBoxAttach
+public partial class ListBoxAttach
 {
     public static readonly DependencyProperty SelectedItemsProperty = DependencyProperty.RegisterAttached(
         "SelectedItems", typeof(IList), typeof(ListBoxAttach),