diff --git a/pkg/content/content.go b/pkg/content/content.go
index 92b612a3..f544c57f 100644
--- a/pkg/content/content.go
+++ b/pkg/content/content.go
@@ -162,36 +162,37 @@ func (content *Content) Abort(ctx context.Context, ref string) error {
 
 func (content *Content) Writer(ctx context.Context, opts ...content.WriterOpt) (content.Writer, error) {
 	writer, err := content.store.Writer(ctx, opts...)
-	return &LocalWriter{
+	return &localWriter{
 		writer: writer,
 	}, err
 }
 
-type LocalWriter struct {
+// localWriter wrap the content.Writer
+type localWriter struct {
 	writer content.Writer
 }
 
-func (localWriter *LocalWriter) Close() error {
+func (localWriter *localWriter) Close() error {
 	return localWriter.writer.Close()
 }
 
-func (localWriter *LocalWriter) Write(p []byte) (int, error) {
+func (localWriter *localWriter) Write(p []byte) (int, error) {
 	return localWriter.writer.Write(p)
 }
 
-func (localWriter *LocalWriter) Digest() digest.Digest {
+func (localWriter *localWriter) Digest() digest.Digest {
 	return localWriter.writer.Digest()
 }
 
-func (localWriter *LocalWriter) Truncate(size int64) error {
+func (localWriter *localWriter) Truncate(size int64) error {
 	return localWriter.writer.Truncate(size)
 }
 
-func (localWriter *LocalWriter) Commit(ctx context.Context, size int64, expected digest.Digest, opts ...content.Opt) error {
+func (localWriter *localWriter) Commit(ctx context.Context, size int64, expected digest.Digest, opts ...content.Opt) error {
 	// we don't write any lables, drop the opts
 	return localWriter.writer.Commit(ctx, size, expected)
 }
 
-func (localWriter *LocalWriter) Status() (st content.Status, err error) {
+func (localWriter *localWriter) Status() (st content.Status, err error) {
 	return localWriter.writer.Status()
 }