diff --git a/Terminal.Gui/Views/ComboBox.cs b/Terminal.Gui/Views/ComboBox.cs
index 8f2022186..615ce3255 100644
--- a/Terminal.Gui/Views/ComboBox.cs
+++ b/Terminal.Gui/Views/ComboBox.cs
@@ -326,7 +326,7 @@ namespace Terminal.Gui {
 			if (string.IsNullOrEmpty (search.Text.ToString ()))
 				ResetSearchSet ();
 			else
-				searchset = source.ToList().Cast<ustring>().Where (x => x.ToString().StartsWith (search.Text.ToString (), StringComparison.CurrentCultureIgnoreCase)).ToList();
+				searchset = source.ToList().Cast<object>().Where (x => x.ToString().StartsWith (search.Text.ToString (), StringComparison.CurrentCultureIgnoreCase)).ToList();
 
 			listview.SetSource (searchset);
 			listview.Height = CalculatetHeight ();