diff --git a/scripts/backup b/scripts/backup
index c5233fc..214b288 100755
--- a/scripts/backup
+++ b/scripts/backup
@@ -10,29 +10,6 @@
 source ../settings/scripts/_common.sh
 source /usr/share/yunohost/helpers
 
-#=================================================
-# MANAGE SCRIPT FAILURE
-#=================================================
-
-#REMOVEME? ynh_clean_setup () {
-	### Remove this function if there's nothing to clean before calling the remove script.
-	true
-}
-# Exit if an error occurs during the execution of the script
-#REMOVEME? ynh_abort_if_errors
-
-#=================================================
-# LOAD SETTINGS
-#=================================================
-#REMOVEME? ynh_print_info --message="Loading installation settings..."
-
-#REMOVEME? app=$YNH_APP_INSTANCE_NAME
-
-#REMOVEME? #REMOVEME? install_dir=$(ynh_app_setting_get --app=$app --key=install_dir)
-#REMOVEME? domain=$(ynh_app_setting_get --app=$app --key=domain)
-#REMOVEME? db_name=$(ynh_app_setting_get --app=$app --key=db_name)
-#REMOVEME? phpversion=$(ynh_app_setting_get --app=$app --key=phpversion)
-
 #=================================================
 # DECLARE DATA AND CONF FILES TO BACKUP
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index d49c15a..181ce07 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -23,19 +23,19 @@ upgrade_type=$(ynh_check_app_version_changed)
 ynh_script_progression --message="Ensuring downward compatibility..." --weight=1
 
 # If fpm_footprint doesn't exist, create it
-if [ -z "$fpm_footprint" ]; then
+if [ -z "${fpm_footprint:-}" ]; then
     fpm_footprint=low
     ynh_app_setting_set --app=$app --key=fpm_footprint --value=$fpm_footprint
 fi
 
 # If fpm_free_footprint doesn't exist, create it
-if [ -z "$fpm_free_footprint" ]; then
+if [ -z "${fpm_free_footprint:-}" ]; then
     fpm_free_footprint=0
     ynh_app_setting_set --app=$app --key=fpm_free_footprint --value=$fpm_free_footprint
 fi
 
 # If fpm_usage doesn't exist, create it
-if [ -z "$fpm_usage" ]; then
+if [ -z "${fpm_usage:-}" ]; then
     fpm_usage=low
     ynh_app_setting_set --app=$app --key=fpm_usage --value=$fpm_usage
 fi