diff --git a/Editor/Utils/Utils.VRCSDK.cs b/Editor/Utils/Utils.VRCSDK.cs
new file mode 100644
index 000000000..bc4a82af1
--- /dev/null
+++ b/Editor/Utils/Utils.VRCSDK.cs
@@ -0,0 +1,29 @@
+using System.Collections.Generic;
+using UnityEngine;
+using VRC.Dynamics;
+
+namespace Anatawa12.AvatarOptimizer
+{
+    partial class Utils
+    {
+        public static Transform GetTarget(this VRCPhysBoneBase physBoneBase) =>
+            physBoneBase.rootTransform ? physBoneBase.rootTransform : physBoneBase.transform;
+
+        public static IEnumerable<Transform> GetAffectedTransforms(this VRCPhysBoneBase physBoneBase)
+        {
+            var ignores = new HashSet<Transform>(physBoneBase.ignoreTransforms);
+            var queue = new Queue<Transform>();
+            queue.Enqueue(physBoneBase.GetTarget());
+
+            while (queue.Count != 0)
+            {
+                var transform = queue.Dequeue();
+                yield return transform;
+
+                foreach (var child in transform.DirectChildrenEnumerable())
+                    if (!ignores.Contains(child))
+                        queue.Enqueue(child);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/Editor/Utils/Utils.VRCSDK.cs.meta b/Editor/Utils/Utils.VRCSDK.cs.meta
new file mode 100644
index 000000000..fcc751ec4
--- /dev/null
+++ b/Editor/Utils/Utils.VRCSDK.cs.meta
@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 456c4b01ce34433d8ca9cc8bb6f0902c
+timeCreated: 1698634433
\ No newline at end of file
diff --git a/Editor/Utils/Utils.cs b/Editor/Utils/Utils.cs
index db5f345a0..e664dbf6a 100644
--- a/Editor/Utils/Utils.cs
+++ b/Editor/Utils/Utils.cs
@@ -75,28 +75,6 @@ public static T GetOrAddComponent<T>(this GameObject go) where T : Component
             return component;
         }
 
-#if AAO_VRCSDK3_AVATARS
-        public static Transform GetTarget(this VRC.Dynamics.VRCPhysBoneBase physBoneBase) =>
-            physBoneBase.rootTransform ? physBoneBase.rootTransform : physBoneBase.transform;
-
-        public static IEnumerable<Transform> GetAffectedTransforms(this VRC.Dynamics.VRCPhysBoneBase physBoneBase)
-        {
-            var ignores = new HashSet<Transform>(physBoneBase.ignoreTransforms);
-            var queue = new Queue<Transform>();
-            queue.Enqueue(physBoneBase.GetTarget());
-
-            while (queue.Count != 0)
-            {
-                var transform = queue.Dequeue();
-                yield return transform;
-
-                foreach (var child in transform.DirectChildrenEnumerable())
-                    if (!ignores.Contains(child))
-                        queue.Enqueue(child);
-            }
-        }
-#endif
-
         public static GameObject NewGameObject(string name, Transform parent)
         {
             var rootObject = new GameObject(name);