diff --git a/Assets/_ModularAvatar/EditModeTests/DuplicateObjectNameTest.cs b/Assets/_ModularAvatar/EditModeTests/DuplicateObjectNameTest.cs
new file mode 100644
index 00000000..e02d63d9
--- /dev/null
+++ b/Assets/_ModularAvatar/EditModeTests/DuplicateObjectNameTest.cs
@@ -0,0 +1,21 @@
+using modular_avatar_tests;
+using nadena.dev.modular_avatar.core.editor;
+using NUnit.Framework;
+
+namespace _ModularAvatar.EditModeTests
+{
+    public class DuplicateObjectNameTest : TestBase
+    {
+        [Test]
+        public void test_duplicate_object_names()
+        {
+            var avatar = CreateRoot("root");
+            var c1 = CreateChild(avatar, "child");
+            var c2 = CreateChild(avatar, "child");
+
+            PathMappings.Init(avatar);
+            c2.gameObject.name = "child2";
+            Assert.AreEqual(PathMappings.MapPath("child"), "child");
+        }
+    }
+}
\ No newline at end of file
diff --git a/Assets/_ModularAvatar/EditModeTests/DuplicateObjectNameTest.cs.meta b/Assets/_ModularAvatar/EditModeTests/DuplicateObjectNameTest.cs.meta
new file mode 100644
index 00000000..76d0de40
--- /dev/null
+++ b/Assets/_ModularAvatar/EditModeTests/DuplicateObjectNameTest.cs.meta
@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 3ef07dec7e1d439586f2b925d89483b8
+timeCreated: 1692505855
\ No newline at end of file
diff --git a/Packages/nadena.dev.modular-avatar/Editor/PathMappings.cs b/Packages/nadena.dev.modular-avatar/Editor/PathMappings.cs
index 790d2b07..9bf32a51 100644
--- a/Packages/nadena.dev.modular-avatar/Editor/PathMappings.cs
+++ b/Packages/nadena.dev.modular-avatar/Editor/PathMappings.cs
@@ -1,18 +1,18 @@
 /*
  * MIT License
- * 
+ *
  * Copyright (c) 2022 bd_
- * 
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in all
  * copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -25,6 +25,7 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using NUnit.Framework;
+using Serilog.Sinks.File;
 using UnityEditor;
 using UnityEngine;
 using VRC.SDKBase.Editor.BuildPipeline;
@@ -150,7 +151,7 @@ namespace nadena.dev.modular_avatar.core.editor
         {
             if (cache != null) return cache;
 
-            ImmutableDictionary<string, string>.Builder builder = ImmutableDictionary.CreateBuilder<string, string>();
+            ImmutableDictionary<string, string> dict = ImmutableDictionary<string, string>.Empty;
 
             foreach (var kvp in _objectToOriginalPaths)
             {
@@ -168,11 +169,14 @@ namespace nadena.dev.modular_avatar.core.editor
                 var newPath = RuntimeUtil.AvatarRootPath(obj);
                 foreach (var origPath in paths)
                 {
-                    builder.Add(origPath, newPath);
+                    if (!dict.ContainsKey(origPath))
+                    {
+                        dict = dict.Add(origPath, newPath);
+                    }
                 }
             }
 
-            cache = builder.ToImmutableDictionary();
+            cache = dict;
             return cache;
         }