diff --git a/Elwig/Helpers/ControlUtils.cs b/Elwig/Helpers/ControlUtils.cs
index 010b660..d8f11e1 100644
--- a/Elwig/Helpers/ControlUtils.cs
+++ b/Elwig/Helpers/ControlUtils.cs
@@ -10,13 +10,16 @@ using System.Windows.Media;
 namespace Elwig.Helpers {
     public class ControlUtils {
 
+        public enum RenewSourceDefault {
+            None,
+            IfOnly,
+            First
+        }
+
         private static void SetControlBrush(Control input, Brush brush) {
             if (input is ComboBox cb) {
                 var border = GetComboBoxBorder(cb);
                 if (border != null) border.BorderBrush = brush;
-            } else if (input is Xceed.Wpf.Toolkit.CheckComboBox ccb) {
-                var border = GetComboBoxBorder(ccb);
-                if (border != null) border.BorderBrush = brush;
             } else {
                 input.BorderBrush = brush;
             }
@@ -33,8 +36,6 @@ namespace Elwig.Helpers {
         public static void ClearInputState(Control input) {
             if (input is ComboBox cb) {
                 GetComboBoxBorder(cb)?.ClearValue(Border.BorderBrushProperty);
-            } else if (input is Xceed.Wpf.Toolkit.CheckComboBox ccb) {
-                GetComboBoxBorder(ccb)?.ClearValue(Border.BorderBrushProperty);
             } else {
                 input.ClearValue(Control.BorderBrushProperty);
             }
@@ -45,11 +46,6 @@ namespace Elwig.Helpers {
             return toggleButton?.Template.FindName("templateRoot", toggleButton) as Border;
         }
 
-        private static Border? GetComboBoxBorder(Xceed.Wpf.Toolkit.CheckComboBox ccb) {
-            var toggleButton = ccb.Template.FindName("toggleButton", ccb) as ToggleButton;
-            return toggleButton?.Template.FindName("templateRoot", toggleButton) as Border;
-        }
-
         public static IEnumerable<T> FindAllChildren<T>(DependencyObject depObj) where T : DependencyObject {
             if (depObj == null)
                 yield return (T)Enumerable.Empty<T>();
@@ -82,12 +78,6 @@ namespace Elwig.Helpers {
             return null;
         }
 
-        public enum RenewSourceDefault {
-            None,
-            IfOnly,
-            First
-        }
-
         public static void RenewItemsSource(Selector selector, IEnumerable? source, Func<object?, object?> getId, SelectionChangedEventHandler? handler = null, RenewSourceDefault def = RenewSourceDefault.None) {
             if (selector.ItemsSource == source)
                 return;