diff --git a/conf/.env.example b/conf/.env.example
index b469a66..3e77129 100644
--- a/conf/.env.example
+++ b/conf/.env.example
@@ -15,7 +15,7 @@ APP_DEBUG=false
 APP_KEY=SomeRandomString
 
 # Application URL
-APP_URL=https://__DOMAIN____PATH__
+APP_URL=__APP_URL_DOMAIN__
 
 # Application default language
 APP_LANG=__LANGUAGE__
diff --git a/scripts/change_url b/scripts/change_url
index 7b4dcec..c685d71 100644
--- a/scripts/change_url
+++ b/scripts/change_url
@@ -33,6 +33,7 @@ db_name=$(ynh_app_setting_get --app=$app --key=db_name)
 db_user=$db_name
 db_pwd=$(ynh_app_setting_get --app=$app --key=mysqlpwd)
 phpversion=$YNH_PHP_VERSION
+app_url_domain=$(ynh_app_setting_get --app=$app --key=app_url_domain)
 
 #=================================================
 # BACKUP BEFORE UPGRADE THEN ACTIVE TRAP
@@ -104,7 +105,7 @@ fi
 ynh_script_progression --message="Reconfiguring congif file.." --weight=1
 
 pushd $final_path
-	yes | php$phpversion artisan bookstack:update-url https://${domain}${path_url} https://${new_domain}${new_path}
+	yes | php$phpversion artisan bookstack:update-url $app_url_domain https://${new_domain}${new_path%/}
 popd
 
 sed -i "/APP_URL=/c\APP_URL=https://${new_domain}${new_path}" $final_path/.env
diff --git a/scripts/install b/scripts/install
index 4502fc5..ab146e8 100644
--- a/scripts/install
+++ b/scripts/install
@@ -119,6 +119,9 @@ ynh_install_composer --phpversion=$phpversion --workdir=$final_path --install_ar
 #=================================================
 ynh_script_progression --message="Adding a configuration file..." --weight=1
 
+app_url_domain="https://$domain${path_url%/}"
+ynh_app_setting_set --app=$app --key=app_url_domain --value=$app_url_domain
+
 ynh_add_config --template=../conf/.env.example --destination=$final_path/.env
 chmod 600 $final_path/.env
 
diff --git a/scripts/upgrade b/scripts/upgrade
index 125665e..f92a40e 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -26,6 +26,7 @@ db_pwd=$(ynh_app_setting_get --app=$app --key=mysqlpwd)
 phpversion=$YNH_PHP_VERSION
 redis_db=$(ynh_app_setting_get --app=$app --key=redis_db)
 mail_pwd=$(ynh_string_random --length=12)
+app_url_domain=$(ynh_app_setting_get --app=$app --key=app_url_domain)
 
 #=================================================
 # CHECK VERSION
@@ -47,6 +48,24 @@ ynh_clean_setup () {
 # Exit if an error occurs during the execution of the script
 ynh_abort_if_errors
 
+#=================================================
+# ENSURE DOWNWARD COMPATIBILITY
+#=================================================
+ynh_script_progression --message="Ensuring downward compatibility..." --weight=1
+
+# If app_url_domain doesn't exist, create it
+if [ -z "$app_url_domain" ]; then
+	app_url_domain="https://$domain${path_url%/}"
+	ynh_app_setting_set --app=$app --key=app_url_domain --value=$app_url_domain
+fi
+
+# Cleaning legacy permissions
+if ynh_legacy_permissions_exists; then
+	ynh_legacy_permissions_delete_all
+
+	ynh_app_setting_delete --app=$app --key=is_public
+fi
+
 #=================================================
 # CREATE DEDICATED USER
 #=================================================