diff --git a/internal/multiplex/datagramBuffer.go b/internal/multiplex/datagramBuffer.go
index 6c1e9fe..397fc4e 100644
--- a/internal/multiplex/datagramBuffer.go
+++ b/internal/multiplex/datagramBuffer.go
@@ -64,6 +64,7 @@ func (d *datagramBuffer) Write(f Frame) error {
 		}
 		d.rwCond.Wait()
 	}
+	// TODO: deal with closing frame here
 	data := make([]byte, len(f.Payload))
 	copy(data, f.Payload)
 	d.buf = append(d.buf, data)
diff --git a/internal/multiplex/streamBuffer.go b/internal/multiplex/streamBuffer.go
index 5182ba7..44cd147 100644
--- a/internal/multiplex/streamBuffer.go
+++ b/internal/multiplex/streamBuffer.go
@@ -12,7 +12,6 @@ package multiplex
 
 import (
 	"container/heap"
-	"errors"
 	"fmt"
 	"sync"
 )
@@ -60,8 +59,6 @@ func NewStreamBuffer() *streamBuffer {
 	return sb
 }
 
-var ClosingFrameReceived = errors.New("closed by closing frame")
-
 // recvNewFrame is a forever running loop which receives frames unordered,
 // cache and order them and send them into sortedBufCh
 func (sb *streamBuffer) Write(f Frame) error {
@@ -70,9 +67,8 @@ func (sb *streamBuffer) Write(f Frame) error {
 	// when there'fs no ooo packages in heap and we receive the next package in order
 	if len(sb.sh) == 0 && f.Seq == sb.nextRecvSeq {
 		if f.Closing == 1 {
-			// empty data indicates closing signal
 			sb.buf.Close()
-			return ClosingFrameReceived
+			return nil
 		} else {
 			sb.buf.Write(f.Payload)
 			sb.nextRecvSeq += 1
@@ -91,7 +87,7 @@ func (sb *streamBuffer) Write(f Frame) error {
 		if f.Closing == 1 {
 			// empty data indicates closing signal
 			sb.buf.Close()
-			return ClosingFrameReceived
+			return nil
 		} else {
 			sb.buf.Write(f.Payload)
 			sb.nextRecvSeq += 1