diff --git a/Scripts/Format/VRMFormat.cs b/Scripts/Format/VRMFormat.cs
index ebff260fc..8121179d5 100644
--- a/Scripts/Format/VRMFormat.cs
+++ b/Scripts/Format/VRMFormat.cs
@@ -8,8 +8,7 @@ namespace VRM
     [Serializable]
     public class glTF_VRM_extensions : JsonSerializableBase
     {
-        [Obsolete("use gltf.asset.generator")]
-        public string version = VRMVersion.VERSION;
+        public string exporterVersion = "UniVRM-" + VRMVersion.VERSION;
 
         public glTF_VRM_Meta meta = new glTF_VRM_Meta();
         public glTF_VRM_Humanoid humanoid = new glTF_VRM_Humanoid();
@@ -20,7 +19,7 @@ namespace VRM
 
         protected override void SerializeMembers(JsonFormatter f)
         {
-            //f.KeyValue(() => version);
+            f.KeyValue(() => exporterVersion);
             f.KeyValue(() => meta);
             f.KeyValue(() => humanoid);
             f.KeyValue(() => firstPerson);