diff --git a/core/modules/node/lib/Drupal/node/Plugin/Core/Entity/Node.php b/core/modules/node/lib/Drupal/node/Plugin/Core/Entity/Node.php
index 61439b1..c2a48d2 100644
--- a/core/modules/node/lib/Drupal/node/Plugin/Core/Entity/Node.php
+++ b/core/modules/node/lib/Drupal/node/Plugin/Core/Entity/Node.php
@@ -187,7 +187,12 @@ public function isPublished() {
    * {@inheritdoc}
    */
   public function getAuthor() {
-    return $this->get('uid')->entity->getBCEntity();
+    $entity = $this->get('uid')->entity;
+    // If no user is given, default to the anonymous user.
+    if (!$entity) {
+      return user_load(0)->getBCentity();
+    }
+    return $entity->getBCEntity();
   }
 
   /**
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index 30497c4..903e876 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -2822,13 +2822,13 @@ function node_query_node_access_alter(AlterableInterface $query) {
  * via hook_node_access_records_alter() implementations, and saves the collected
  * and altered grants to the database.
  *
- * @param \Drupal\Core\Entity\EntityInterface $node
+ * @param \Drupal\node\NodeInterface $node
  *   The $node to acquire grants for.
  * @param $delete
  *   (optional) Whether to delete existing node access records before inserting
  *   new ones. Defaults to TRUE.
  */
-function node_access_acquire_grants(\Drupal\node\NodeInterface $node, $delete = TRUE) {
+function node_access_acquire_grants(NodeInterface $node, $delete = TRUE) {
   $grants = module_invoke_all('node_access_records', $node);
   // Let modules alter the grants.
   drupal_alter('node_access_records', $grants, $node);