diff --git a/scripts/upgrade b/scripts/upgrade
index 64d2333..493011e 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -57,12 +57,11 @@ if [ -z "$max_file_size" ]; then
 	ynh_app_setting_set --app=$app --key=max_file_size --value=$max_file_size
 fi
 
-# Make app public if necessary
-if [ $is_public -eq 1 ]
-then
-	# Everyone can access the app.
-	# The "main" permission is automatically created before the install script.
-	ynh_permission_update --permission="main" --add="visitors"
+# Cleaning legacy permissions
+if ynh_legacy_permissions_exists; then
+	ynh_legacy_permissions_delete_all
+
+	ynh_app_setting_delete --app=$app --key=is_public
 fi
 
 #=================================================