diff --git a/client/main.go b/client/main.go
index 34b25a5..7631cbb 100644
--- a/client/main.go
+++ b/client/main.go
@@ -51,9 +51,7 @@ func handleClient(sess *smux.Session, p1 io.ReadWriteCloser, quiet bool) {
 		die := make(chan struct{})
 		go func() {
 			buf := xmitBuf.Get().([]byte)
-			if _, err := generic.CopyBuffer(dst, src, buf); err != nil {
-				logln(err)
-			}
+			generic.CopyBuffer(dst, src, buf)
 			xmitBuf.Put(buf)
 		}()
 		return die
diff --git a/go.mod b/go.mod
index 8f88f68..c7ecd66 100644
--- a/go.mod
+++ b/go.mod
@@ -9,7 +9,7 @@ require (
 	github.com/templexxx/xor v0.0.0-20181023030647-4e92f724b73b // indirect
 	github.com/tjfoc/gmsm v1.0.1 // indirect
 	github.com/urfave/cli v1.20.0
-	github.com/xtaci/kcp-go v5.3.5+incompatible
+	github.com/xtaci/kcp-go v5.3.6+incompatible
 	github.com/xtaci/smux v1.2.11
 	golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529
 	golang.org/x/net v0.0.0-20190509222800-a4d6f7feada5 // indirect
diff --git a/go.sum b/go.sum
index 6181b4b..308bf03 100644
--- a/go.sum
+++ b/go.sum
@@ -46,6 +46,8 @@ github.com/xtaci/kcp-go v5.3.4+incompatible h1:vHlrCvUC4nDSGQQxbgzwwF35sup3mKAxr
 github.com/xtaci/kcp-go v5.3.4+incompatible/go.mod h1:bN6vIwHQbfHaHtFpEssmWsN45a+AZwO7eyRCmEIbtvE=
 github.com/xtaci/kcp-go v5.3.5+incompatible h1:PD0cqKLJDAMKgX2qzWfK98fbcrVPYDEdstlY0SN0q20=
 github.com/xtaci/kcp-go v5.3.5+incompatible/go.mod h1:bN6vIwHQbfHaHtFpEssmWsN45a+AZwO7eyRCmEIbtvE=
+github.com/xtaci/kcp-go v5.3.6+incompatible h1:g3/sc8dtbFG6td3W7BTyJNr/5Sb0zMNBFgEtqnSuxmw=
+github.com/xtaci/kcp-go v5.3.6+incompatible/go.mod h1:bN6vIwHQbfHaHtFpEssmWsN45a+AZwO7eyRCmEIbtvE=
 github.com/xtaci/smux v1.1.1 h1:ZyIo9XHuHkAeENzHR8yGWC+6xUSCTeP2tPTRE8mnLvc=
 github.com/xtaci/smux v1.1.1/go.mod h1:f+nYm6SpuHMy/SH0zpbvAFHT1QoMcgLOsWcFip5KfPw=
 github.com/xtaci/smux v1.1.2 h1:AeAzHKqvDeFEcicL9Q06LTjIVW2I55iooUbpDRGHth4=
diff --git a/server/main.go b/server/main.go
index c55277a..f307ef9 100644
--- a/server/main.go
+++ b/server/main.go
@@ -79,9 +79,7 @@ func handleClient(p1 *smux.Stream, p2 io.ReadWriteCloser, quiet bool) {
 		die := make(chan struct{})
 		go func() {
 			buf := xmitBuf.Get().([]byte)
-			if _, err := generic.CopyBuffer(dst, src, buf); err != nil {
-				logln(err)
-			}
+			generic.CopyBuffer(dst, src, buf)
 			xmitBuf.Put(buf)
 		}()
 		return die