diff --git a/Packages/UniGLTF/Runtime/UniHumanoid/HumanoidLoader.cs b/Packages/UniGLTF/Runtime/UniHumanoid/HumanoidLoader.cs
index 61f07d70b..db3b5329d 100644
--- a/Packages/UniGLTF/Runtime/UniHumanoid/HumanoidLoader.cs
+++ b/Packages/UniGLTF/Runtime/UniHumanoid/HumanoidLoader.cs
@@ -55,7 +55,10 @@ namespace UniHumanoid
         /// HumanBone のマッピングを流用して、新たな Avatar を作り直す。
         /// 古い Avatar は破棄する。
         /// </summary>
-        public static void RebuildHumanAvatar(Animator animator)
+        /// <remarks>
+        /// This method runs asynchronously only in play mode.
+        /// </remarks>
+        public static async Awaitable RebuildHumanAvatar(Animator animator)
         {
             if (animator == null)
             {
@@ -77,6 +80,9 @@ namespace UniHumanoid
             if (Application.isPlaying)
             {
                 GameObject.Destroy(animator);
+
+                // Else, the following AddComponent call will fail.
+                await Awaitable.NextFrameAsync();
             }
             else
             {
diff --git a/Packages/VRM/Runtime/SkinnedMeshUtility/VRMBoneNormalizer.cs b/Packages/VRM/Runtime/SkinnedMeshUtility/VRMBoneNormalizer.cs
index 77269756d..5d0762c06 100644
--- a/Packages/VRM/Runtime/SkinnedMeshUtility/VRMBoneNormalizer.cs
+++ b/Packages/VRM/Runtime/SkinnedMeshUtility/VRMBoneNormalizer.cs
@@ -53,7 +53,10 @@ namespace VRM
         /// <param name="go">対象モデルのルート</param>
         /// <param name="forceTPose">強制的にT-Pose化するか</param>
         /// <param name="useCurrentBlendShapeWeight">BlendShape の現状をbakeするか</param>
-        public static void Execute(GameObject go, bool forceTPose, bool useCurrentBlendShapeWeight)
+        /// <remarks>
+        /// This method runs asynchronously only in play mode.
+        /// </remarks>
+        public static async Awaitable Execute(GameObject go, bool forceTPose, bool useCurrentBlendShapeWeight)
         {
             if (forceTPose)
             {
@@ -83,7 +86,7 @@ namespace VRM
             // 回転とスケールが除去された新しいヒエラルキーからAvatarを作る
             if (go.TryGetComponent<Animator>(out var animator))
             {
-                HumanoidLoader.RebuildHumanAvatar(animator);
+                await HumanoidLoader.RebuildHumanAvatar(animator);
             }
         }