diff --git a/proxy/vmess/encoding/commands.go b/proxy/vmess/encoding/commands.go
index 1b61f777..11d93d67 100644
--- a/proxy/vmess/encoding/commands.go
+++ b/proxy/vmess/encoding/commands.go
@@ -41,12 +41,12 @@ func MarshalCommand(command interface{}, writer io.Writer) error {
 	}
 
 	auth := Authenticate(buffer.Bytes())
-	len := buffer.Len() + 4
-	if len > 255 {
+	length := buffer.Len() + 4
+	if length > 255 {
 		return ErrCommandTooLarge
 	}
 
-	common.Must2(writer.Write([]byte{cmdID, byte(len), byte(auth >> 24), byte(auth >> 16), byte(auth >> 8), byte(auth)}))
+	common.Must2(writer.Write([]byte{cmdID, byte(length), byte(auth >> 24), byte(auth >> 16), byte(auth >> 8), byte(auth)}))
 	common.Must2(writer.Write(buffer.Bytes()))
 	return nil
 }
diff --git a/transport/internet/udp/hub.go b/transport/internet/udp/hub.go
index 9ac25db3..2da7a5cf 100644
--- a/transport/internet/udp/hub.go
+++ b/transport/internet/udp/hub.go
@@ -17,9 +17,9 @@ type Payload struct {
 
 type HubOption func(h *Hub)
 
-func HubCapacity(cap int) HubOption {
+func HubCapacity(capacity int) HubOption {
 	return func(h *Hub) {
-		h.capacity = cap
+		h.capacity = capacity
 	}
 }