diff --git a/webrtc/Sdp.cpp b/webrtc/Sdp.cpp
index e7e5cdb0..c517d4e2 100644
--- a/webrtc/Sdp.cpp
+++ b/webrtc/Sdp.cpp
@@ -1149,10 +1149,8 @@ RtcSessionSdp::Ptr RtcSession::toRtcSessionSdp() const{
                     auto msid = std::make_shared<SdpAttrMsid>();
                     if (!m.rtp_rtx_ssrc[0].msid.empty()) {
                         msid->parse(m.rtp_rtx_ssrc[0].msid);
-                    } else {
-                        msid->parse("mslabel label");
+                        sdp_media.items.emplace_back(wrapSdpAttr(std::move(msid)));
                     }
-                    sdp_media.items.emplace_back(wrapSdpAttr(std::move(msid)));
                 }
             }
 
diff --git a/webrtc/WebRtcEchoTest.cpp b/webrtc/WebRtcEchoTest.cpp
index d2ad8e92..879c6ce7 100644
--- a/webrtc/WebRtcEchoTest.cpp
+++ b/webrtc/WebRtcEchoTest.cpp
@@ -40,7 +40,9 @@ void WebRtcEchoTest::onCheckSdp(SdpType type, RtcSession &sdp) {
     if (type == SdpType::answer) {
         for (auto &m : sdp.media) {
             for (auto &ssrc : m.rtp_rtx_ssrc) {
-                ssrc.msid = "zlmediakit msid";
+                if (!ssrc.msid.empty()) {
+                    ssrc.msid = "zlmediakit msid";
+                }
             }
         }
     }