diff --git a/core/logger.go b/core/logger.go
index 855a826..ad20232 100644
--- a/core/logger.go
+++ b/core/logger.go
@@ -18,6 +18,7 @@
 package core
 
 import (
+	"github.com/xtaci/smux"
 	"log"
 	"net"
 	"net/http"
@@ -33,3 +34,7 @@ func logConnErr(conn net.Conn, err error) {
 func logRequestErr(r *http.Request, err error) {
 	errLogger.Printf("request from %s %s: %v", r.RemoteAddr, r.RequestURI, err)
 }
+
+func logMuxSessErr(s *smux.Session, err error) {
+	errLogger.Printf("mux session %s <-> %s: %v", s.RemoteAddr(), s.LocalAddr(), err)
+}
diff --git a/core/smux.go b/core/smux.go
index 3cab12a..aae392f 100644
--- a/core/smux.go
+++ b/core/smux.go
@@ -22,7 +22,6 @@ import (
 	"fmt"
 	"github.com/xtaci/smux"
 	"io"
-	"log"
 	"net"
 	"sync"
 	"time"
@@ -115,7 +114,7 @@ func (m *MuxTransport) tryGetStream() (stream *smux.Stream) {
 
 		s, err := sess.OpenStream()
 		if err != nil {
-			log.Printf("sess err: %v", err)
+			logMuxSessErr(sess, err)
 			sess.Close()
 			m.sm.Lock()
 			delete(m.sess, sess)