diff --git a/go.mod b/go.mod
index fdca9ecb9..5df7cab57 100644
--- a/go.mod
+++ b/go.mod
@@ -4,7 +4,7 @@ require (
 	github.com/golang/snappy v0.0.4
 	github.com/pkg/errors v0.9.1
 	github.com/urfave/cli v1.22.14
-	github.com/xtaci/kcp-go/v5 v5.6.3
+	github.com/xtaci/kcp-go/v5 v5.6.5
 	github.com/xtaci/smux v1.5.24
 	github.com/xtaci/tcpraw v1.2.25
 	golang.org/x/crypto v0.14.0
diff --git a/go.sum b/go.sum
index 61f6b082c..c2f2852ed 100644
--- a/go.sum
+++ b/go.sum
@@ -61,6 +61,8 @@ github.com/urfave/cli v1.22.14 h1:ebbhrRiGK2i4naQJr+1Xj92HXZCrK7MsyTS/ob3HnAk=
 github.com/urfave/cli v1.22.14/go.mod h1:X0eDS6pD6Exaclxm99NJ3FiCDRED7vIHpx2mDOHLvkA=
 github.com/xtaci/kcp-go/v5 v5.6.3 h1:yd59SKXdJ0PBxeMBy3apalxFCEmBLGgQmL6nP46tU0g=
 github.com/xtaci/kcp-go/v5 v5.6.3/go.mod h1:uIuw2KEg3FcmEdS4PeXHaGty9Ui7NYb1WKIrSDwpMg4=
+github.com/xtaci/kcp-go/v5 v5.6.5 h1:oxGZNobj3OddrLzwdJYnR/waNgwrL98u02u0DWNHE3k=
+github.com/xtaci/kcp-go/v5 v5.6.5/go.mod h1:Qy3Zf2tWTdFdEs0E8JvhrX+39r5UDZoYac8anvud7/Q=
 github.com/xtaci/lossyconn v0.0.0-20190602105132-8df528c0c9ae h1:J0GxkO96kL4WF+AIT3M4mfUVinOCPgf2uUWYFUzN0sM=
 github.com/xtaci/lossyconn v0.0.0-20190602105132-8df528c0c9ae/go.mod h1:gXtu8J62kEgmN++bm9BVICuT/e8yiLI2KFobd/TRFsE=
 github.com/xtaci/smux v1.5.24 h1:77emW9dtnOxxOQ5ltR+8BbsX1kzcOxQ5gB+aaV9hXOY=
diff --git a/vendor/github.com/xtaci/kcp-go/v5/fec.go b/vendor/github.com/xtaci/kcp-go/v5/fec.go
index 88f5a9c4b..27dd66e2a 100644
--- a/vendor/github.com/xtaci/kcp-go/v5/fec.go
+++ b/vendor/github.com/xtaci/kcp-go/v5/fec.go
@@ -45,7 +45,8 @@ type fecDecoder struct {
 	codec reedsolomon.Encoder
 
 	// auto tune fec parameter
-	autoTune autoTune
+	autoTune   autoTune
+	shouldTune bool
 }
 
 func newFECDecoder(dataShards, parityShards int) *fecDecoder {
@@ -78,18 +79,17 @@ func (dec *fecDecoder) decode(in fecPacket) (recovered [][]byte) {
 	}
 
 	// check if FEC parameters is out of sync
-	var shouldTune bool
 	if int(in.seqid())%dec.shardSize < dec.dataShards {
 		if in.flag() != typeData { // expect typeData
-			shouldTune = true
+			dec.shouldTune = true
 		}
 	} else {
 		if in.flag() != typeParity {
-			shouldTune = true
+			dec.shouldTune = true
 		}
 	}
 
-	if shouldTune {
+	if dec.shouldTune {
 		autoDS := dec.autoTune.FindPeriod(true)
 		autoPS := dec.autoTune.FindPeriod(false)
 
@@ -108,11 +108,17 @@ func (dec *fecDecoder) decode(in fecPacket) (recovered [][]byte) {
 				dec.codec = codec
 				dec.decodeCache = make([][]byte, dec.shardSize)
 				dec.flagCache = make([]bool, dec.shardSize)
+				dec.shouldTune = false
 				//log.Println("autotune to :", dec.dataShards, dec.parityShards)
 			}
 		}
 	}
 
+	// parameters in tuning
+	if dec.shouldTune {
+		return nil
+	}
+
 	// insertion
 	n := len(dec.rx) - 1
 	insertIdx := 0
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 1a80b3539..65887fd77 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -35,7 +35,7 @@ github.com/tjfoc/gmsm/sm4
 # github.com/urfave/cli v1.22.14
 ## explicit; go 1.11
 github.com/urfave/cli
-# github.com/xtaci/kcp-go/v5 v5.6.3
+# github.com/xtaci/kcp-go/v5 v5.6.5
 ## explicit; go 1.21
 github.com/xtaci/kcp-go/v5
 # github.com/xtaci/smux v1.5.24