diff --git a/client.go b/client.go
index 1c3b45f..d4cd9c1 100644
--- a/client.go
+++ b/client.go
@@ -99,7 +99,7 @@ type internalDataMessage struct {
 	Data interface{} `json:"data"`
 }
 
-type internalDataVAD struct {
+type InternalDataVAD struct {
 	Type string                            `json:"type"`
 	Data voiceactivedetector.VoiceActivity `json:"data"`
 }
@@ -849,11 +849,14 @@ func (c *Client) renegotiate() {
 	c.log.Debug("client: renegotiate")
 	c.negotiationNeeded.Store(true)
 
+	c.muCallback.Lock()
 	if c.onRenegotiation == nil {
+		c.muCallback.Unlock()
 		c.log.Errorf("client: onRenegotiation is not set, can't do renegotiation")
 
 		return
 	}
+	c.muCallback.Unlock()
 
 	if c.isInRemoteNegotiation.Load() {
 		c.log.Infof("sfu: renegotiation is delayed because the remote client %s is doing negotiation ", c.ID)
@@ -1035,6 +1038,20 @@ func (c *Client) ClientTracks() map[string]iClientTrack {
 	return clientTracks
 }
 
+func readRTCP(r *webrtc.RTPSender, b []byte) ([]rtcp.Packet, interceptor.Attributes, error) {
+	i, attributes, err := r.Read(b)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	pkts, err := rtcp.Unmarshal(b[:i])
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return pkts, attributes, nil
+}
+
 // TODO: need to improve and reduce goroutine usage
 func (c *Client) enableReportAndStats(rtpSender *webrtc.RTPSender, track iClientTrack) {
 	ssrc := rtpSender.GetParameters().Encodings[0].SSRC
@@ -1045,6 +1062,8 @@ func (c *Client) enableReportAndStats(rtpSender *webrtc.RTPSender, track iClient
 		clientCtx, cancelClientCtx := context.WithCancel(c.context)
 		defer cancelClientCtx()
 
+		b := make([]byte, 1500)
+
 		for {
 			select {
 			case <-clientCtx.Done():
@@ -1052,7 +1071,7 @@ func (c *Client) enableReportAndStats(rtpSender *webrtc.RTPSender, track iClient
 			case <-localCtx.Done():
 				return
 			default:
-				rtcpPackets, _, err := rtpSender.ReadRTCP()
+				rtcpPackets, _, err := readRTCP(rtpSender, b)
 				if err != nil && (err == io.EOF || err == io.ErrClosedPipe) {
 					return
 				}
@@ -1764,7 +1783,7 @@ func (c *Client) enableSendVADToInternalDataChannel() {
 }
 
 func (c *Client) sendVad(dataType string, activity voiceactivedetector.VoiceActivity) {
-	dataMessage := internalDataVAD{
+	dataMessage := InternalDataVAD{
 		Type: dataType,
 		Data: activity,
 	}