diff --git a/utils/decode_auth.go b/utils/decode_auth.go
index 13ff4c5..b790387 100644
--- a/utils/decode_auth.go
+++ b/utils/decode_auth.go
@@ -2,15 +2,18 @@ package main
 
 import (
 	"encoding/base64"
+	"flag"
 	"fmt"
 	"ntlm/messages"
 )
 
 func main() {
+	var ntlmVersion = flag.Int("ntlm", 2, "NTLM version to try: 1 or 2")
+	flag.Parse()
 	var data string
-	fmt.Println("Paste the base64 encoded Authenticate message:")
+	fmt.Println("Paste the base64 encoded Authenticate message (with no line breaks):")
 	fmt.Scanf("%s", &data)
 	authenticateData, _ := base64.StdEncoding.DecodeString(data)
-	a, _ := messages.ParseAuthenticateMessage(authenticateData, 2)
+	a, _ := messages.ParseAuthenticateMessage(authenticateData, *ntlmVersion)
 	fmt.Printf(a.String())
 }