diff --git a/Scripts/Format/VRMMaterialImporter.cs b/Scripts/Format/VRMMaterialImporter.cs
index 73cffe612..12d2d9556 100644
--- a/Scripts/Format/VRMMaterialImporter.cs
+++ b/Scripts/Format/VRMMaterialImporter.cs
@@ -9,7 +9,7 @@ namespace VRM
     public class VRMMaterialImporter : MaterialImporter
     {
         List<glTF_VRM_Material> m_materials;
-        public VRMMaterialImporter(ImporterContext context, List<glTF_VRM_Material> materials) : base(new ShaderStore(context, "VRM/UnlitTexture"), context)
+        public VRMMaterialImporter(ImporterContext context, List<glTF_VRM_Material> materials) : base(new ShaderStore(context), context)
         {
             m_materials = materials;
         }
diff --git a/Scripts/Format/glTF_VRM_Material.cs b/Scripts/Format/glTF_VRM_Material.cs
index 71fc7f0dc..664a701da 100644
--- a/Scripts/Format/glTF_VRM_Material.cs
+++ b/Scripts/Format/glTF_VRM_Material.cs
@@ -27,6 +27,14 @@ namespace VRM
             // "Queue",
         };
 
+        private static readonly string[] VRMExtensionShaders = new string[]
+        {
+            "VRM/UnlitTransparentZWrite",
+            "VRM/MToon"
+        };
+
+        private static readonly string VRM_USE_GLTFSHADER = "VRM_USE_GLTFSHADER";
+
         protected override void SerializeMembers(GLTFJsonFormatter f)
         {
             f.KeyValue(() => name);
@@ -112,6 +120,12 @@ namespace VRM
                 renderQueue = m.renderQueue,
             };
 
+            if (!VRMExtensionShaders.Contains(m.shader.name))
+            {
+                material.shader = VRM_USE_GLTFSHADER;
+                return material;
+            }
+
             var prop = PreShaderPropExporter.GetPropsForSupportedShader(m.shader.name);
             if (prop == null)
             {
diff --git a/UniGLTF b/UniGLTF
index fae0f5e1f..8f04b09b5 160000
--- a/UniGLTF
+++ b/UniGLTF
@@ -1 +1 @@
-Subproject commit fae0f5e1f44f8c0fe06c9fd2c61ac99e513c7141
+Subproject commit 8f04b09b5cb7c12ad0f49b6aaa66800029258f77