diff --git a/serial.go b/serial.go
index 0b403da..6c933a0 100644
--- a/serial.go
+++ b/serial.go
@@ -39,13 +39,13 @@ type SerialPortError struct {
 }
 
 const (
-	ERROR_PORT_BUSY           = 1
-	ERROR_PORT_NOT_FOUND      = 2
-	ERROR_INVALID_SERIAL_PORT = 3
-	ERROR_PERMISSION_DENIED   = 4
-	ERROR_INVALID_PORT_SPEED  = 5
-	ERROR_ENUMERATING_PORTS   = 6
-	ERROR_OTHER               = 99
+	ERROR_PORT_BUSY = iota
+	ERROR_PORT_NOT_FOUND
+	ERROR_INVALID_SERIAL_PORT
+	ERROR_PERMISSION_DENIED
+	ERROR_INVALID_PORT_SPEED
+	ERROR_ENUMERATING_PORTS
+	ERROR_OTHER
 )
 
 func (e SerialPortError) Error() string {