diff --git a/scripts/upgrade b/scripts/upgrade
index bde9cc0..bb64e10 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -100,8 +100,9 @@ fi
 #=================================================
 backup_before_upgrade=$(ynh_app_setting_get --app=$app --key=backup_before_upgrade)
 if [ -z "$backup_before_upgrade" ] ; then
-  if [ $(ynh_app_setting_get --app=$app --key=disable_backup_before_upgrade) ] ; then
-  backup_before_upgrade="false"
+    disable_backup_before_upgrade=$(ynh_app_setting_get --app=$app --key=disable_backup_before_upgrade)
+    if [ $disable_backup_before_upgrade ] ; then
+        backup_before_upgrade="false"
 fi
 
 #=================================================