core/modules/aggregator/aggregator.routing.yml                   | 3 +++
 .../modules/entity_test/src/Controller/EntityTestController.php  | 9 +++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/core/modules/aggregator/aggregator.routing.yml b/core/modules/aggregator/aggregator.routing.yml
index 2f2d553..508a5de 100644
--- a/core/modules/aggregator/aggregator.routing.yml
+++ b/core/modules/aggregator/aggregator.routing.yml
@@ -84,3 +84,6 @@ aggregator.page_last:
     _title: 'Feed aggregator'
   requirements:
     _permission: 'access news feeds'
+  options:
+    # @todo Add cacheability metadata to this response.
+    no_cache: TRUE
diff --git a/core/modules/system/tests/modules/entity_test/src/Controller/EntityTestController.php b/core/modules/system/tests/modules/entity_test/src/Controller/EntityTestController.php
index 1d6e4e8..33eb14b 100644
--- a/core/modules/system/tests/modules/entity_test/src/Controller/EntityTestController.php
+++ b/core/modules/system/tests/modules/entity_test/src/Controller/EntityTestController.php
@@ -105,12 +105,16 @@ public function testAdmin() {
    *   A renderable array.
    */
   public function listReferencingEntities($entity_reference_field_name, $referenced_entity_type, $referenced_entity_id) {
+    $build = [
+      '#cache' => [],
+    ];
+
     // Early return if the referenced entity does not exist (or is deleted).
     $referenced_entity = $this->entityManager()
       ->getStorage($referenced_entity_type)
       ->load($referenced_entity_id);
     if ($referenced_entity === NULL) {
-      return array();
+      return $build;
     }
 
     $query = $this->entityQueryFactory
@@ -119,9 +123,10 @@ public function listReferencingEntities($entity_reference_field_name, $reference
     $entities = $this->entityManager()
       ->getStorage('entity_test')
       ->loadMultiple($query->execute());
-    return $this->entityManager()
+    $build += $this->entityManager()
       ->getViewBuilder('entity_test')
       ->viewMultiple($entities, 'full');
+    return $build;
   }
 
   /**