diff --git a/common/buf/reader.go b/common/buf/reader.go
index 124e3e3a..632a0039 100644
--- a/common/buf/reader.go
+++ b/common/buf/reader.go
@@ -58,21 +58,16 @@ var (
 )
 
 type BufferedReader struct {
-	stream       Reader
-	legacyReader io.Reader
-	leftOver     MultiBuffer
-	buffered     bool
+	stream   Reader
+	leftOver MultiBuffer
+	buffered bool
 }
 
 func NewBufferedReader(reader Reader) *BufferedReader {
-	r := &BufferedReader{
+	return &BufferedReader{
 		stream:   reader,
 		buffered: true,
 	}
-	if lr, ok := reader.(io.Reader); ok {
-		r.legacyReader = lr
-	}
-	return r
 }
 
 func (r *BufferedReader) SetBuffered(f bool) {
@@ -99,8 +94,10 @@ func (r *BufferedReader) Read(b []byte) (int, error) {
 		return nBytes, nil
 	}
 
-	if !r.buffered && r.legacyReader != nil {
-		return r.legacyReader.Read(b)
+	if !r.buffered {
+		if reader, ok := r.stream.(io.Reader); ok {
+			return reader.Read(b)
+		}
 	}
 
 	mb, err := r.stream.ReadMultiBuffer()
diff --git a/common/buf/writer.go b/common/buf/writer.go
index a6bada13..6dbc886e 100644
--- a/common/buf/writer.go
+++ b/common/buf/writer.go
@@ -48,23 +48,18 @@ var (
 
 // BufferedWriter is a Writer with internal buffer.
 type BufferedWriter struct {
-	writer       Writer
-	legacyWriter io.Writer
-	buffer       *Buffer
-	buffered     bool
+	writer   Writer
+	buffer   *Buffer
+	buffered bool
 }
 
 // NewBufferedWriter creates a new BufferedWriter.
 func NewBufferedWriter(writer Writer) *BufferedWriter {
-	w := &BufferedWriter{
+	return &BufferedWriter{
 		writer:   writer,
 		buffer:   New(),
 		buffered: true,
 	}
-	if lw, ok := writer.(io.Writer); ok {
-		w.legacyWriter = lw
-	}
-	return w
 }
 
 func (w *BufferedWriter) WriteByte(c byte) error {
@@ -74,8 +69,10 @@ func (w *BufferedWriter) WriteByte(c byte) error {
 
 // Write implements io.Writer.
 func (w *BufferedWriter) Write(b []byte) (int, error) {
-	if !w.buffered && w.legacyWriter != nil {
-		return w.legacyWriter.Write(b)
+	if !w.buffered {
+		if writer, ok := w.writer.(io.Writer); ok {
+			return writer.Write(b)
+		}
 	}
 
 	totalBytes := 0