diff --git a/scripts/_common.sh b/scripts/_common.sh
index f8f7923..1cb1ebb 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -15,7 +15,7 @@ lowercase(){
     echo "$1" | sed "y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/"
 }
 
-os=`lowercase \`uname -s\``
+OS=`lowercase \`uname -s\``
 mach=`uname -m`
 if [ ${mach} = "armv6l" ]
 then
diff --git a/scripts/install b/scripts/install
index d108c12..6d06bc6 100755
--- a/scripts/install
+++ b/scripts/install
@@ -10,32 +10,30 @@ source _common.sh
 source /usr/share/yunohost/helpers
 
 #=================================================
-# RETRIEVE ARGUMENTS FROM THE MANIFEST
+# STORE SETTINGS
 #=================================================
+ynh_script_progression --message="Storing installation settings..."
 
+#Will be used in restore script to check that we're restoring on the same OS/Board type
+ynh_app_setting_set --app="$app" --key=OS --value="$OS"
+ynh_app_setting_set --app="$app" --key=mach --value="$mach"
+
+#Settings for mosquitto. We store empty values so that they may be automatically retrieved and bound in other scripts.
+if [ "$domain" == "$mqtt_domain" ]; then 
+	mqtt_domain=""
+	#packaging v2 : settings are automatically stored. We overide the values
+	ynh_app_setting_set --app="$app" --key=mqtt_domain --value="$mqtt_domain"
+	ynh_app_setting_set --app="$app" --key=mqtt_port --value=""
+	ynh_app_setting_set --app="$app" --key=mqtt_websocket_port --value=""
+fi
+
+#path used by api to read/update domoticz
 #Set dedicated variables
 if [ "$path" == "/" ]; then
 	api_path=/api_/"$app"
 else
 	api_path=/api_"$path"
 fi
-
-if [ "$domain" == "$mqtt_domain" ]; then 
-	mqtt_domain=""
-	#pacakging v2 : settings are automatically stored. We don't want mqtt_domain in this case
-	ynh_app_setting_delete --app="$app" --key=mqtt_domain
-fi
-
-#=================================================
-# STORE SETTINGS FROM MANIFEST
-#=================================================
-ynh_script_progression --message="Storing installation settings..."
-
-#Will be used in restore script to check that we're restoring on the same OS/Board type
-ynh_app_setting_set --app="$app" --key=OS --value="$os"
-ynh_app_setting_set --app="$app" --key=mach --value="$mach"
-
-#path used by api to read/update domoticz
 ynh_app_setting_set --app="$app" --key=api_path --value="$api_path"
 
 #=================================================
diff --git a/scripts/restore b/scripts/restore
index 8c328ea..4c47fa0 100755
--- a/scripts/restore
+++ b/scripts/restore
@@ -11,8 +11,8 @@ source ../settings/scripts/_common.sh
 source /usr/share/yunohost/helpers
 
 #Have to reload them as otherwise they are all the same
-backup_OS=$(ynh_app_setting_get --app="$app" --key=OS)
-backup_mach=$(ynh_app_setting_get --app="$app" --key=mach)
+#backup_OS=$(ynh_app_setting_get --app="$app" --key=OS)
+#backup_mach=$(ynh_app_setting_get --app="$app" --key=mach)
 current_os=`lowercase \`uname -s\``
 current_mach=`uname -m`
 
@@ -22,11 +22,14 @@ current_mach=`uname -m`
 #As we are downloading compiled binaries for each system, we have to check if the restore occurs
 #on the same system type. If we are restoring on another system type it won't work and in that
 #case we must go through a reinstall process.
-test "$backup_OS" = "$current_os" \
+test "$OS" = "$current_os" \
 	|| ynh_die --message="Cannot restore : previous OS is $backup_OS, current OS is $current_os, please reinstall"
-test "$backup_mach" = "$current_mach" \
+test "$mach" = "$current_mach" \
 	|| ynh_die --message="Cannot restore : previous machine type is $backup_mach, current machine type is $current_mach, please reinstall"
 
+ynh_app_setting_set --app="$app" --key=OS --value="$OS"
+ynh_app_setting_set --app="$app" --key=mach --value="$mach"
+
 #=================================================
 # STANDARD RESTORATION STEPS
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index 9a65e80..020f1b0 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -13,12 +13,6 @@ version_gt() {
 source _common.sh
 source /usr/share/yunohost/helpers
 
-current_OS=$(ynh_app_setting_get --app="$app" --key=OS)
-current_mach=$(ynh_app_setting_get --app="$app" --key=mach)
-mqtt_domain=$(ynh_app_setting_get --app="$app" --key=mqtt_domain)
-mqtt_port=$(ynh_app_setting_get --app="$app" --key=mqtt_port)
-mqtt_websocket_port=$(ynh_app_setting_get --app="$app" --key=mqtt_websocket_port)
-
 #=================================================
 # CHECK VERSION
 #=================================================
@@ -41,10 +35,10 @@ ynh_systemd_action --service_name="$app" --action="stop" --log_path="/var/log/$a
 ynh_script_progression --message="Ensuring downward compatibility..."
 
 #Store OS and machine (to be used in restore script)
-if [ -z "$current_OS" ]; then
+if [ -z "$OS" ]; then
 	ynh_app_setting_set --app="$app" --key=OS --value="$OS"
 fi
-if [ -z "$current_mach" ]; then
+if [ -z "$mach" ]; then
 	ynh_app_setting_set --app="$app" --key=mach --value="$MACH"
 fi
 
@@ -63,24 +57,41 @@ if [ -z "$api_path" ]; then
 	ynh_app_setting_set --app="$app" --key=api_path --value="$api_path"
 fi
 
+#Need to be kept for backward compatibility : previous version did not have settings stored and
+#variable may not be bound.
+mqtt_domain=$(ynh_app_setting_get --app="$app" --key=mqtt_domain)
+if [[ -z "$mqtt_domain" ]]; then
+	ynh_app_setting_set --app="$app" --key=mqtt_domain --value="$mqtt_domain"
+fi
+
 #Port to listen for MQTT internal
+#first we read from manifest to ensure variable is bound
+mqtt_port=$(ynh_app_setting_get --app="$app" --key=mqtt_port)
+#then we store the setting in the manifest so it is automatically loaded for other scritps
+ynh_app_setting_set --app="$app" --key=mqtt_port --value="$mqtt_port"
+#then if a domain has been provided (manually for example to install mosquitto afterward), we assign a port in case it is empty.
 if [[ -z "$mqtt_port" && ! -z "$mqtt_domain" ]]; then
  	mqtt_port=$(ynh_find_port --port="$default_mqtt_port")
  	ynh_app_setting_set --app="$app" --key=mqtt_port --value="$mqtt_port"
 fi
 
 #Port to listen for MQTT websocket
+#first we read from manifest to ensure variable is bound
+mqtt_websocket_port=$(ynh_app_setting_get --app="$app" --key=mqtt_websocket_port)
+#then we store the setting in the manifest so it is automatically loaded for other scritps
+ynh_app_setting_set --app="$app" --key=mqtt_websocket_port --value="$mqtt_websocket_port"
+#then if a domain has been provided (manually for example to install mosquitto afterward), we assign a port in case it is empty.
 if [[ -z "$mqtt_websocket_port" && ! -z "$mqtt_domain" ]]; then
  	mqtt_websocket_port=$(ynh_find_port --port="$default_mqtt_websocket_port")
  	ynh_app_setting_set --app="$app" --key=mqtt_websocket_port --value="$mqtt_websocket_port"
 fi
 
 # Create the permission "domoticz_API" only if it doesn't exist.
-if ! ynh_permission_exists --permission="domoticz_API"
-then
+#if ! ynh_permission_exists --permission="domoticz_API"
+#then
 	# API Authorization with dedicated URL
-	ynh_permission_create --permission="domoticz_API" --label="api" --url="$domain$api_path" --allowed="visitors" --show_tile="false" --protected="true"
-fi
+#	ynh_permission_create --permission="domoticz_API" --label="api" --url="$domain$api_path" --allowed="visitors" --show_tile="false" --protected="true"
+#fi
 
 # Create the permission "domoticz_MQTT" only if it doesn't exist.
 if [ ! -z "$mqtt_domain" ]; then