diff --git a/src/BootstrapBlazor/Components/Select/SelectTree.razor.cs b/src/BootstrapBlazor/Components/Select/SelectTree.razor.cs
index 3d9c97131ff..f2664e41ea4 100644
--- a/src/BootstrapBlazor/Components/Select/SelectTree.razor.cs
+++ b/src/BootstrapBlazor/Components/Select/SelectTree.razor.cs
@@ -212,7 +212,7 @@ private async Task TriggerItemChanged(Func<TreeViewItem<TValue>, bool> predicate
         }
     }
 
-    private IEnumerable<TreeViewItem<TValue>> GetExpandedItems()
+    private List<TreeViewItem<TValue>> GetExpandedItems()
     {
         if (ItemCache != Items)
         {