diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/BuiltInRP/Import/BuiltInGltfMaterialDescriptorGenerator.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/BuiltInRP/Import/BuiltInGltfMaterialDescriptorGenerator.cs
index eda109fb4..03ffca198 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/BuiltInRP/Import/BuiltInGltfMaterialDescriptorGenerator.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/BuiltInRP/Import/BuiltInGltfMaterialDescriptorGenerator.cs
@@ -13,26 +13,15 @@ namespace UniGLTF
         {
             if (BuiltInGltfUnlitMaterialImporter.TryCreateParam(data, i, out var param)) return param;
             if (BuiltInGltfPbrMaterialImporter.TryCreateParam(data, i, out param)) return param;
+
             // fallback
             if (Symbols.VRM_DEVELOP)
             {
                 Debug.LogWarning($"material: {i} out of range. fallback");
             }
-
-            return new MaterialDescriptor(
-                GltfMaterialImportUtils.ImportMaterialName(i, null),
-                BuiltInGltfPbrMaterialImporter.Shader,
-                null,
-                new Dictionary<string, TextureDescriptor>(),
-                new Dictionary<string, float>(),
-                new Dictionary<string, Color>(),
-                new Dictionary<string, Vector4>(),
-                new Action<Material>[]{});
+            return GetGltfDefault(GltfMaterialImportUtils.ImportMaterialName(i, null));
         }
 
-        public MaterialDescriptor GetGltfDefault()
-        {
-            return BuiltInGltfDefaultMaterialImporter.CreateParam();
-        }
+        public MaterialDescriptor GetGltfDefault(string materialName = null) => BuiltInGltfDefaultMaterialImporter.CreateParam(materialName);
     }
 }
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/BuiltInRP/Import/Materials/BuiltInGltfDefaultMaterialImporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/BuiltInRP/Import/Materials/BuiltInGltfDefaultMaterialImporter.cs
index b59d94bc7..c6f8112d8 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/BuiltInRP/Import/Materials/BuiltInGltfDefaultMaterialImporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/BuiltInRP/Import/Materials/BuiltInGltfDefaultMaterialImporter.cs
@@ -9,11 +9,11 @@ namespace UniGLTF
     /// </summary>
     public static class BuiltInGltfDefaultMaterialImporter
     {
-        public static MaterialDescriptor CreateParam()
+        public static MaterialDescriptor CreateParam(string materialName = null)
         {
             // FIXME
             return new MaterialDescriptor(
-                "__default__",
+                string.IsNullOrEmpty(materialName) ? "__default__" : materialName,
                 BuiltInGltfPbrMaterialImporter.Shader,
                 default,
                 new Dictionary<string, TextureDescriptor>(),
diff --git a/Assets/VRM/Runtime/IO/MaterialIO/BuiltInRP/Import/BuiltInVrmMaterialDescriptorGenerator.cs b/Assets/VRM/Runtime/IO/MaterialIO/BuiltInRP/Import/BuiltInVrmMaterialDescriptorGenerator.cs
index aae706af3..b48387cd0 100644
--- a/Assets/VRM/Runtime/IO/MaterialIO/BuiltInRP/Import/BuiltInVrmMaterialDescriptorGenerator.cs
+++ b/Assets/VRM/Runtime/IO/MaterialIO/BuiltInRP/Import/BuiltInVrmMaterialDescriptorGenerator.cs
@@ -41,21 +41,13 @@ namespace VRM
             }
 
             // fallback
-            Debug.LogWarning($"fallback");
-            return new MaterialDescriptor(
-                GltfMaterialImportUtils.ImportMaterialName(i, null),
-                BuiltInGltfPbrMaterialImporter.Shader,
-                null,
-                new Dictionary<string, TextureDescriptor>(),
-                new Dictionary<string, float>(),
-                new Dictionary<string, Color>(),
-                new Dictionary<string, Vector4>(),
-                new Action<Material>[]{});
+            if (Symbols.VRM_DEVELOP)
+            {
+                Debug.LogWarning($"material: {i} out of range. fallback");
+            }
+            return GetGltfDefault(GltfMaterialImportUtils.ImportMaterialName(i, null));
         }
 
-        public MaterialDescriptor GetGltfDefault()
-        {
-            return BuiltInGltfDefaultMaterialImporter.CreateParam();
-        }
+        public MaterialDescriptor GetGltfDefault(string materialName = null) => BuiltInGltfDefaultMaterialImporter.CreateParam(materialName);
     }
 }
diff --git a/Assets/VRM10/Runtime/IO/Material/BuiltInRP/Import/BuiltInVrm10MaterialDescriptorGenerator.cs b/Assets/VRM10/Runtime/IO/Material/BuiltInRP/Import/BuiltInVrm10MaterialDescriptorGenerator.cs
index ec6b09115..15d27c2e6 100644
--- a/Assets/VRM10/Runtime/IO/Material/BuiltInRP/Import/BuiltInVrm10MaterialDescriptorGenerator.cs
+++ b/Assets/VRM10/Runtime/IO/Material/BuiltInRP/Import/BuiltInVrm10MaterialDescriptorGenerator.cs
@@ -21,20 +21,9 @@ namespace UniVRM10
             {
                 Debug.LogWarning($"material: {i} out of range. fallback");
             }
-            return new MaterialDescriptor(
-                GltfMaterialImportUtils.ImportMaterialName(i, null),
-                BuiltInGltfPbrMaterialImporter.Shader,
-                null, 
-                new Dictionary<string, TextureDescriptor>(),
-                new Dictionary<string, float>(),
-                new Dictionary<string, Color>(),
-                new Dictionary<string, Vector4>(),
-                new Action<Material>[]{});
+            return GetGltfDefault(GltfMaterialImportUtils.ImportMaterialName(i, null));
         }
 
-        public MaterialDescriptor GetGltfDefault()
-        {
-            return BuiltInGltfDefaultMaterialImporter.CreateParam();
-        }
+        public MaterialDescriptor GetGltfDefault(string materialName = null) => BuiltInGltfDefaultMaterialImporter.CreateParam(materialName);
     }
 }