diff --git a/Scripts/Format/VRMExporter.cs b/Scripts/Format/VRMExporter.cs
index a79c5fde5..61345c9cc 100644
--- a/Scripts/Format/VRMExporter.cs
+++ b/Scripts/Format/VRMExporter.cs
@@ -14,7 +14,9 @@ namespace VRM
         }
 
         public VRMExporter(glTF gltf) : base(gltf)
-        { }
+        {
+            gltf.extensionsUsed.Add(glTF_VRM_extensions.ExtensionName);
+        }
 
         public new static glTF Export(GameObject go)
         {
diff --git a/Scripts/Format/VRMFormat.cs b/Scripts/Format/VRMFormat.cs
index 078f3c4dc..5c4d695db 100644
--- a/Scripts/Format/VRMFormat.cs
+++ b/Scripts/Format/VRMFormat.cs
@@ -5,18 +5,6 @@ using UniJSON;
 
 namespace UniGLTF
 {
-    public partial class glTFUsedExtensions
-    {
-        [UsedExtension]
-        static string VRMGetUsedExtension
-        {
-            get
-            {
-                return "VRM";
-            }
-        }
-    }
-
     public partial class glTF_extensions : ExtensionsBase<glTF_extensions>
     {
         public VRM.glTF_VRM_extensions VRM = new VRM.glTF_VRM_extensions();
@@ -38,6 +26,14 @@ VRM extension is for 3d humanoid avatars (and models) in VR applications.
 ")]
     public class glTF_VRM_extensions : JsonSerializableBase
     {
+        public static string ExtensionName
+        {
+            get
+            {
+                return "VRM";
+            }
+        }
+
         [JsonSchema(Description = @"Version of exporter that vrm created. " + VRMVersion.VRM_VERSION)]
         public string exporterVersion = "UniVRM-" + VRMVersion.VERSION;
 
diff --git a/UniGLTF b/UniGLTF
index 871137c94..fb2fa4f1b 160000
--- a/UniGLTF
+++ b/UniGLTF
@@ -1 +1 @@
-Subproject commit 871137c94e8c288c8cabe3d3d48ef42fcdf5c087
+Subproject commit fb2fa4f1b6f2ed39f65f5235b14a10ab1f8db3df