diff --git a/fec.go b/fec.go
index 7d43543..e2a4ab6 100644
--- a/fec.go
+++ b/fec.go
@@ -288,7 +288,7 @@ type (
 	}
 )
 
-func newFECEncoder(dataShards, parityShards, offset, minRTO int) *fecEncoder {
+func newFECEncoder(dataShards, parityShards, offset int) *fecEncoder {
 	if dataShards <= 0 || parityShards <= 0 {
 		return nil
 	}
diff --git a/sess.go b/sess.go
index a4a1b45..227d99b 100644
--- a/sess.go
+++ b/sess.go
@@ -154,9 +154,9 @@ func newUDPSession(conv uint32, dataShards, parityShards int, l *Listener, conn
 	// FEC codec initialization
 	sess.fecDecoder = newFECDecoder(dataShards, parityShards)
 	if sess.block != nil {
-		sess.fecEncoder = newFECEncoder(dataShards, parityShards, cryptHeaderSize, IKCP_RTO_DEF)
+		sess.fecEncoder = newFECEncoder(dataShards, parityShards, cryptHeaderSize)
 	} else {
-		sess.fecEncoder = newFECEncoder(dataShards, parityShards, 0, IKCP_RTO_DEF)
+		sess.fecEncoder = newFECEncoder(dataShards, parityShards, 0)
 	}
 
 	// calculate additional header size introduced by FEC and encryption