diff --git a/core/lib/Drupal/Core/Routing/RouteBuilder.php b/core/lib/Drupal/Core/Routing/RouteBuilder.php
index fe90787..6488236 100644
--- a/core/lib/Drupal/Core/Routing/RouteBuilder.php
+++ b/core/lib/Drupal/Core/Routing/RouteBuilder.php
@@ -233,7 +233,7 @@ public function destruct() {
    *   A route collection.
    */
   protected function applyLowerCaseCollection(RouteCollection $collection) {
-    foreach ($collection->getAll() as $route) {
+    foreach ($collection->all() as $route) {
       // Force each path to be lower case.
       $path = Unicode::strtolower($route->getPath());
       $route->setPath($path);