diff --git a/Packages/nadena.dev.modular-avatar/Editor/Inspector/MergeArmatureEditor.cs b/Packages/nadena.dev.modular-avatar/Editor/Inspector/MergeArmatureEditor.cs
index bba5dc64..b057240b 100644
--- a/Packages/nadena.dev.modular-avatar/Editor/Inspector/MergeArmatureEditor.cs
+++ b/Packages/nadena.dev.modular-avatar/Editor/Inspector/MergeArmatureEditor.cs
@@ -101,8 +101,7 @@ namespace nadena.dev.modular_avatar.core.editor
 
             EditorGUILayout.Separator();
 
-            var enable_name_assignment =
-                target.mergeTarget.Get(RuntimeUtil.FindAvatarInParents(target.transform)) != null;
+            var enable_name_assignment = target.mergeTarget.Get(target) != null;
             using (var scope = new EditorGUI.DisabledScope(!enable_name_assignment))
             {
                 if (GUILayout.Button(G("merge_armature.adjust_names")))
@@ -114,4 +113,4 @@ namespace nadena.dev.modular_avatar.core.editor
             Localization.ShowLanguageUI();
         }
     }
-}
\ No newline at end of file
+}