diff --git a/Assets/VRM/UniUnlit/Editor/UniUnlitEditor.cs b/Assets/VRM/UniUnlit/Editor/UniUnlitEditor.cs
index 5aadb6f47..544b18b80 100644
--- a/Assets/VRM/UniUnlit/Editor/UniUnlitEditor.cs
+++ b/Assets/VRM/UniUnlit/Editor/UniUnlitEditor.cs
@@ -124,14 +124,24 @@ namespace UniGLTF.UniUnlit
         
         private static bool PopupEnum<T>(string name, MaterialProperty property, MaterialEditor editor) where T : struct
         {
+            if (!typeof(T).IsEnum) return false;
+            
             EditorGUI.showMixedValue = property.hasMixedValue;
             EditorGUI.BeginChangeCheck();
-            var ret = EditorGUILayout.Popup(name, (int) property.floatValue, Enum.GetNames(typeof(T)));
+            var values = (T[]) Enum.GetValues(typeof(T));
+            var names = Enum.GetNames(typeof(T));
+
+            var currInt = (int) property.floatValue;
+            var currValue = (T) Enum.ToObject(typeof(T), currInt);
+            var currIndex = Array.IndexOf(values, currValue);
+            var nextIndex = EditorGUILayout.Popup(name, currIndex, names);
             var changed = EditorGUI.EndChangeCheck();
             if (changed)
             {
                 editor.RegisterPropertyChangeUndo("EnumPopUp");
-                property.floatValue = ret;
+                var nextValue = values[nextIndex];
+                var nextInt = (int) (object) nextValue;
+                property.floatValue = nextInt;
             }
             EditorGUI.showMixedValue = false;
             return changed;