--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
@@ -164,6 +164,7 @@ public function getConstraints() {
         ]);
       }
     }
+    return $constraints;
   }
 
   /**
--- a/core/modules/field/src/Tests/Update/EntityReferenceTargetBundleUpdateTest.php
+++ b/core/modules/field/src/Tests/Update/EntityReferenceTargetBundleUpdateTest.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\field\Tests\Update;
 
-use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\system\Tests\Update\UpdatePathTestBase;
 
 /**
@@ -32,21 +31,22 @@ protected function setDatabaseDumpFiles() {
    * @see field_update_8001()
    */
   public function testFieldUpdate8001() {
-    // Load the 'node.field_tags' field storage, and check it has the legacy
-    // 'target_bundle' storage setting set to NULL.
-    /** @var \Drupal\field\FieldStorageConfigInterface */
-    $field_storage = FieldStorageConfig::load('node.field_tags');
-    $settings = $field_storage->getSettings();
-    $this->assertTrue(array_key_exists('target_bundle', $settings));
-    $this->assertNull($settings['target_bundle']);
+    $configFactory = $this->container->get('config.factory');
+
+    // Add the deprecated 'target_bundle' setting to the 'node.field_tags' field
+    // storage config.
+    /** @var \Drupal\Core\Config\Config */
+    $config = $configFactory->getEditable('field.storage.node.field_tags');
+    $config->set('settings.target_bundle', NULL);
+    $config->save(TRUE);
 
     // Run updates.
     $this->runUpdates();
 
-    // Load the field storage again, and check the 'target_bundle' setting has
-    // been removed.
-    $field_storage = FieldStorageConfig::load('node.field_tags');
-    $settings = $field_storage->getSettings();
+    // Reload the config, and check that the 'target_bundle' setting has been
+    // removed.
+    $config = $configFactory->getEditable('field.storage.node.field_tags');
+    $settings = $config->get('settings');
     $this->assertFalse(array_key_exists('target_bundle', $settings));
   }