diff --git a/Assets/UniGLTF/Runtime/UniGLTF/Format/ExtensionsAndExtras/gltf_mesh_extras_targetNames.cs b/Assets/UniGLTF/Runtime/UniGLTF/Format/ExtensionsAndExtras/gltf_mesh_extras_targetNames.cs
index f1036bb61..4a276480a 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/Format/ExtensionsAndExtras/gltf_mesh_extras_targetNames.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/Format/ExtensionsAndExtras/gltf_mesh_extras_targetNames.cs
@@ -91,7 +91,7 @@ namespace UniGLTF
             return new glTFExtensionExport().Add(ExtraName, f.GetStore().Bytes);
         }
 
-        public static void Serialize(glTFMesh gltfMesh, IEnumerable<string> targetNames)
+        public static void Serialize(glTFMesh gltfMesh, IEnumerable<string> targetNames, BlendShapeTargetNameLocationFlags blendShapeTargetNameLocation)
         {
             // targetNames
             var f = new JsonFormatter();
@@ -103,13 +103,21 @@ namespace UniGLTF
             f.EndList();
             var targetNamesJson = f.GetStore().Bytes;
 
-            var meshExtras = glTFExtensionExport.GetOrCreate(ref gltfMesh.extras);
-            meshExtras.Add(ExtraName, targetNamesJson);
-
-            foreach (var prim in gltfMesh.primitives)
+            // mesh
+            if (blendShapeTargetNameLocation.HasFlag(BlendShapeTargetNameLocationFlags.Mesh))
             {
-                var primExtras = glTFExtensionExport.GetOrCreate(ref prim.extras);
-                primExtras.Add(ExtraName, targetNamesJson);
+                var meshExtras = glTFExtensionExport.GetOrCreate(ref gltfMesh.extras);
+                meshExtras.Add(ExtraName, targetNamesJson);
+            }
+
+            // primitive
+            if (blendShapeTargetNameLocation.HasFlag(BlendShapeTargetNameLocationFlags.Primitives))
+            {
+                foreach (var prim in gltfMesh.primitives)
+                {
+                    var primExtras = glTFExtensionExport.GetOrCreate(ref prim.extras);
+                    primExtras.Add(ExtraName, targetNamesJson);
+                }
             }
         }
     }
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/BlendShapeTargetNameLocationFlags.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/BlendShapeTargetNameLocationFlags.cs
new file mode 100644
index 000000000..ef71a92a7
--- /dev/null
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/BlendShapeTargetNameLocationFlags.cs
@@ -0,0 +1,19 @@
+using System;
+
+namespace UniGLTF
+{
+    /// <summary>
+    /// https://www.khronos.org/registry/glTF/specs/2.0/glTF-2.0.html#meshes
+    /// 
+    /// See Implementation Note about `mesh.extras.targetNames`
+    /// </summary>
+    [Flags]
+    public enum BlendShapeTargetNameLocationFlags
+    {
+        None = 0,
+        Mesh = 1,
+        Primitives = 2,
+
+        Both = Mesh | Primitives,
+    }
+}
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/BlendShapeTargetNameLocationFlags.cs.meta b/Assets/UniGLTF/Runtime/UniGLTF/IO/BlendShapeTargetNameLocationFlags.cs.meta
new file mode 100644
index 000000000..80e72f45c
--- /dev/null
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/BlendShapeTargetNameLocationFlags.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 050edaae24c5b4e45b702dd150deee8a
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_DividedVertexBuffer.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_DividedVertexBuffer.cs
index fac86a104..67327c87b 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_DividedVertexBuffer.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_DividedVertexBuffer.cs
@@ -129,7 +129,7 @@ namespace UniGLTF
             }
 
             var targetNames = Enumerable.Range(0, mesh.blendShapeCount).Select(x => mesh.GetBlendShapeName(x)).ToArray();
-            gltf_mesh_extras_targetNames.Serialize(gltfMesh, targetNames);
+            gltf_mesh_extras_targetNames.Serialize(gltfMesh, targetNames, BlendShapeTargetNameLocationFlags.Both);
 
             return (gltfMesh, Enumerable.Range(0, mesh.blendShapeCount).ToDictionary(x => x, x => x));
         }
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_SharedVertexBuffer.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_SharedVertexBuffer.cs
index 6da415fcd..aae9f9c9b 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_SharedVertexBuffer.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_SharedVertexBuffer.cs
@@ -188,7 +188,7 @@ namespace UniGLTF
                     }
                 }
 
-                gltf_mesh_extras_targetNames.Serialize(gltfMesh, targetNames);
+                gltf_mesh_extras_targetNames.Serialize(gltfMesh, targetNames, BlendShapeTargetNameLocationFlags.Both);
             }
 
             return (gltfMesh, blendShapeIndexMap);
diff --git a/Assets/VRM10/Runtime/IO/Model/MeshWriter.cs b/Assets/VRM10/Runtime/IO/Model/MeshWriter.cs
index 7a7ef16f7..063607b67 100644
--- a/Assets/VRM10/Runtime/IO/Model/MeshWriter.cs
+++ b/Assets/VRM10/Runtime/IO/Model/MeshWriter.cs
@@ -136,7 +136,7 @@ namespace UniVRM10
             }
 
             var targetNames = src.Meshes[0].MorphTargets.Select(x => x.Name).ToArray();
-            gltf_mesh_extras_targetNames.Serialize(gltfMesh, targetNames);
+            gltf_mesh_extras_targetNames.Serialize(gltfMesh, targetNames, BlendShapeTargetNameLocationFlags.Mesh);
 
             return gltfMesh;
         }