diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/BlendShapeExporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/BlendShapeExporter.cs
index 563b9d2e4..449b9e882 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/BlendShapeExporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/BlendShapeExporter.cs
@@ -44,7 +44,9 @@ namespace UniGLTF
                 var positionAccessorIndex = -1;
                 if (sparseIndices.Length > 0)
                 {
+#if VRM_DEVELOP
                     Debug.LogFormat("Sparse {0}/{1}", sparseIndices.Length, positions.Length);
+#endif
                     var sparseIndicesViewIndex = gltf.ExtendBufferAndGetViewIndex(gltfBuffer, sparseIndices);
                     positionAccessorIndex = gltf.ExtendSparseBufferAndGetAccessorIndex(gltfBuffer, accessorCount, positions, sparseIndices, sparseIndicesViewIndex, glBufferTarget.NONE);
                 }
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_DividedVertexBuffer.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_DividedVertexBuffer.cs
index bd7796073..3c7988919 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_DividedVertexBuffer.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshExporter_DividedVertexBuffer.cs
@@ -89,7 +89,7 @@ namespace UniGLTF
                 // blendShape(morph target)
                 for (int j = 0; j < mesh.blendShapeCount; ++j)
                 {
-                    var blendShape = new MeshExportUtil.BlendShapeBuffer(indices.Length);
+                    var blendShape = new MeshExportUtil.BlendShapeBuffer(usedIndices.Count);
 
                     // aggriage morph target
                     mesh.GetBlendShapeFrameVertices(j, 0, blendShapePositions, blendShapeNormals, null);