diff --git a/common/net/port.go b/common/net/port.go
index fc791e025..1e665550a 100644
--- a/common/net/port.go
+++ b/common/net/port.go
@@ -7,7 +7,7 @@ import (
 type Port serial.Uint16Literal
 
 func PortFromBytes(port []byte) Port {
-	return Port(serial.ParseUint16(port))
+	return Port(serial.BytesLiteral(port).Uint16Value())
 }
 
 func (this Port) Value() uint16 {
diff --git a/common/serial/bytes.go b/common/serial/bytes.go
index ebbfa7591..0b315aa0c 100644
--- a/common/serial/bytes.go
+++ b/common/serial/bytes.go
@@ -10,6 +10,24 @@ func (this BytesLiteral) Value() []byte {
 	return []byte(this)
 }
 
+func (this BytesLiteral) Uint8Value() uint8 {
+	return this.Value()[0]
+}
+
+func (this BytesLiteral) Uint16() Uint16Literal {
+	return Uint16Literal(this.Uint16Value())
+}
+
+func (this BytesLiteral) Uint16Value() uint16 {
+	value := this.Value()
+	return uint16(value[0])<<8 + uint16(value[1])
+}
+
+func (this BytesLiteral) IntValue() int {
+	value := this.Value()
+	return int(value[0])<<24 + int(value[1])<<16 + int(value[2])<<8 + int(value[3])
+}
+
 func (this BytesLiteral) Uint32Value() uint32 {
 	value := this.Value()
 	return uint32(value[0])<<24 +
diff --git a/common/serial/numbers.go b/common/serial/numbers.go
index 235dab182..9de8759cc 100644
--- a/common/serial/numbers.go
+++ b/common/serial/numbers.go
@@ -10,17 +10,6 @@ type Uint16 interface {
 
 type Uint16Literal uint16
 
-func ParseUint16(data []byte) Uint16Literal {
-	switch len(data) {
-	case 0:
-		return Uint16Literal(0)
-	case 1:
-		return Uint16Literal(uint16(data[0]))
-	default:
-		return Uint16Literal(uint16(data[0])<<8 + uint16(data[1]))
-	}
-}
-
 func (this Uint16Literal) String() string {
 	return strconv.Itoa(int(this))
 }
diff --git a/proxy/vmess/command/accounts.go b/proxy/vmess/command/accounts.go
index b01c78770..04516cc98 100644
--- a/proxy/vmess/command/accounts.go
+++ b/proxy/vmess/command/accounts.go
@@ -78,7 +78,7 @@ func (this *SwitchAccount) Unmarshal(data []byte) error {
 	if len(data) < alterIdStart+2 {
 		return transport.CorruptedPacket
 	}
-	this.AlterIds = serial.ParseUint16(data[alterIdStart : alterIdStart+2])
+	this.AlterIds = serial.BytesLiteral(data[alterIdStart : alterIdStart+2]).Uint16()
 	levelStart := alterIdStart + 2
 	if len(data) < levelStart+1 {
 		return transport.CorruptedPacket