diff --git a/Assets/VRM10/Runtime/IO/Model/MeshImporter.cs b/Assets/VRM10/Runtime/IO/Model/MeshImporter.cs
index bf33aed6b..035fdd7df 100644
--- a/Assets/VRM10/Runtime/IO/Model/MeshImporter.cs
+++ b/Assets/VRM10/Runtime/IO/Model/MeshImporter.cs
@@ -112,6 +112,10 @@ namespace UniVRM10
             // 各種パラメーターを再計算
             mesh.RecalculateBounds();
             mesh.RecalculateTangents();
+            if (src.VertexBuffer.Normals == null)
+            {
+                mesh.RecalculateNormals();
+            }
 
             Profiler.EndSample();
 
diff --git a/Assets/VRM10/Runtime/IO/Model/MeshImporterDivided.cs b/Assets/VRM10/Runtime/IO/Model/MeshImporterDivided.cs
index 91d71c6e9..49de5fc71 100644
--- a/Assets/VRM10/Runtime/IO/Model/MeshImporterDivided.cs
+++ b/Assets/VRM10/Runtime/IO/Model/MeshImporterDivided.cs
@@ -42,6 +42,10 @@ namespace UniVRM10
             // 各種データを再構築
             resultMesh.RecalculateBounds();
             resultMesh.RecalculateTangents();
+            if (meshGroup.Meshes.Any(mesh => mesh.VertexBuffer.Normals == null))
+            {
+                resultMesh.RecalculateNormals();
+            }
 
             // BlendShapeを更新
             var blendShapeCount = meshGroup.Meshes[0].MorphTargets.Count;