diff --git a/scripts/install b/scripts/install
index 3d7f9b1..9a2cce8 100644
--- a/scripts/install
+++ b/scripts/install
@@ -20,7 +20,7 @@ email=$(ynh_user_get_info --username="$admin" --key=mail)
 #=================================================
 ynh_script_progression --message="Validating installation parameters..."
 
-if [[ $admin -lt 5 ]]; then
+if [[ ${#admin} -lt 5 ]]; then
     ynh_die --message="Admin username minimum length is 5"
 fi