diff --git a/core/tests/Drupal/Tests/Core/Routing/NullRouteBuilder.php b/core/tests/Drupal/Tests/Core/Routing/NullRouteBuilder.php
index acc2f60..58cb2af 100644
--- a/core/tests/Drupal/Tests/Core/Routing/NullRouteBuilder.php
+++ b/core/tests/Drupal/Tests/Core/Routing/NullRouteBuilder.php
@@ -16,4 +16,7 @@ public function getCollectionDuringRebuild() {
     return FALSE;
   }
 
+  public function rebuildIfNeeded() {
+  }
+
 }