diff --git a/Scripts/SkinnedMeshUtility/Editor/BoneNormalizer.cs b/Scripts/SkinnedMeshUtility/Editor/BoneNormalizer.cs
index 778923f5f..09d7bd788 100644
--- a/Scripts/SkinnedMeshUtility/Editor/BoneNormalizer.cs
+++ b/Scripts/SkinnedMeshUtility/Editor/BoneNormalizer.cs
@@ -320,23 +320,33 @@ namespace VRM
             mesh.name = src.name + "(transformed)";
 
             mesh.vertices = src.vertices.Select(x => m.MultiplyPoint(x)).ToArray();
-            if(src.normals!=null)mesh.normals = src.normals.Select(x => m.MultiplyVector(x)).ToArray();
-            if(src.tangents!=null)mesh.tangents = src.tangents.Select(x =>
+            if (src.normals != null && src.normals.Length > 0)
             {
-                var v = m.MultiplyVector(x);
-                return new Vector4(v.x, v.y, v.z, x.w);
-            }).ToArray();
-            mesh.uv = src.uv;
-            mesh.uv2 = src.uv2;
-            mesh.uv3 = src.uv3;
-            mesh.uv4 = src.uv4;
-            mesh.colors = src.colors;
+                mesh.normals = src.normals.Select(x => m.MultiplyVector(x)).ToArray();
+            }
+            if (src.tangents != null && src.tangents.Length > 0)
+            {
+                mesh.tangents = src.tangents.Select(x =>
+                {
+                    var t = m.MultiplyVector((Vector3)x);
+                    return new Vector4(t.x, t.y, t.z, x.w);
+                }).ToArray();
+            }
+
+            if (src.colors != null && src.colors.Length > 0) mesh.colors = src.colors;
+            if (src.uv != null && src.uv.Length > 0) mesh.uv = src.uv;
+            if (src.uv2 != null && src.uv2.Length > 0) mesh.uv2 = src.uv2;
+            if (src.uv3 != null && src.uv3.Length > 0) mesh.uv3 = src.uv3;
+            if (src.uv4 != null && src.uv4.Length > 0) mesh.uv4 = src.uv4;
+
             mesh.subMeshCount = src.subMeshCount;
             for(int i=0; i<mesh.subMeshCount; ++i)
             {
                 mesh.SetIndices(src.GetIndices(i), src.GetTopology(i), i);
             }
+
             return mesh;
         }
     }
 }
+