diff --git a/lib/public/AppFramework/App.php b/lib/public/AppFramework/App.php
index 016ef5a0318c8333eb749fa8cdf12726cb9edec8..2f55fd451406340121cc50019438a588fcd3b937 100644
--- a/lib/public/AppFramework/App.php
+++ b/lib/public/AppFramework/App.php
@@ -143,6 +143,7 @@ class App {
 	 * @param array $routes
 	 * @since 6.0.0
 	 * @suppress PhanAccessMethodInternal
+	 * @deprecated 20.0.0 Just return an array from your routes.php
 	 */
 	public function registerRoutes(IRouter $router, array $routes) {
 		$routeConfig = new RouteConfig($this->container, $router, $routes);