diff --git a/scripts/mkvm b/scripts/mkvm
index a4ad76e..64e41cb 100755
--- a/scripts/mkvm
+++ b/scripts/mkvm
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-ovarelease="2023b"
+ovarelease="2023a"
 ovafile="$HOME/Téléchargements/debian-bullseye-gsb-${ovarelease}.ova"
 
 
@@ -37,6 +37,10 @@ create_if () {
 }
 
 
+if [[ $# != 1 ]] ; then
+	usage
+fi
+
 vm=$1
 
 create_vm "${vm}"