.../entity_test/src/Entity/EntityTestMapField.php  |   1 +
 .../Hal/EnityTestMapFieldHalJsonAnonTest.php       | 103 +++++++++++++++++++++
 .../Rest/EntityTestMapFieldResourceTestBase.php    |   5 +
 3 files changed, 109 insertions(+)

diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMapField.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMapField.php
index 82bba32..b21d1a0 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMapField.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMapField.php
@@ -15,6 +15,7 @@
  *   entity_keys = {
  *     "id" = "id",
  *     "label" = "name",
+ *     "langcode" = "langcode",
  *   },
  *   admin_permission = "administer entity_test content",
  * )
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EnityTestMapFieldHalJsonAnonTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EnityTestMapFieldHalJsonAnonTest.php
new file mode 100644
index 0000000..af1ef4c
--- /dev/null
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EnityTestMapFieldHalJsonAnonTest.php
@@ -0,0 +1,103 @@
+<?php
+
+namespace Drupal\Tests\entity_test\Functional\Hal;
+
+use Drupal\Tests\entity_test\Functional\Rest\EntityTestMapFieldResourceTestBase;
+use Drupal\Tests\hal\Functional\EntityResource\HalEntityNormalizationTrait;
+use Drupal\Tests\rest\Functional\AnonResourceTestTrait;
+use Drupal\user\Entity\User;
+
+/**
+ * @group hal
+ */
+class EntityTestMapFieldHalJsonAnonTest extends EntityTestMapFieldResourceTestBase {
+
+  use HalEntityNormalizationTrait;
+  use AnonResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['hal'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'hal_json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/hal+json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedNormalizedEntity() {
+    $default_normalization = parent::getExpectedNormalizedEntity();
+
+    $normalization = $this->applyHalFieldNormalization($default_normalization);
+
+    $author = User::load(0);
+    return $normalization + [
+      '_links' => [
+        'self' => [
+          'href' => '',
+        ],
+        'type' => [
+          'href' => $this->baseUrl . '/rest/type/entity_test_map_field/entity_test_map_field',
+        ],
+        $this->baseUrl . '/rest/relation/entity_test_map_field/entity_test_map_field/user_id' => [
+          [
+            'href' => $this->baseUrl . '/user/0?_format=hal_json',
+            'lang' => 'en',
+          ],
+        ],
+      ],
+      '_embedded' => [
+        $this->baseUrl . '/rest/relation/entity_test_map_field/entity_test_map_field/user_id' => [
+          [
+            '_links' => [
+              'self' => [
+                'href' => $this->baseUrl . '/user/0?_format=hal_json',
+              ],
+              'type' => [
+                'href' => $this->baseUrl . '/rest/type/user/user',
+              ],
+            ],
+            'uuid' => [
+              [
+                'value' => $author->uuid(),
+              ],
+            ],
+            'lang' => 'en',
+          ],
+        ],
+      ],
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getNormalizedPostEntity() {
+    return parent::getNormalizedPostEntity() + [
+      '_links' => [
+        'type' => [
+          'href' => $this->baseUrl . '/rest/type/entity_test_map_field/entity_test_map_field',
+        ],
+      ],
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedCacheContexts() {
+    return [
+      'url.site',
+      'user.permissions',
+    ];
+  }
+
+}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestMapFieldResourceTestBase.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestMapFieldResourceTestBase.php
index dcc12b9..183b49d 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestMapFieldResourceTestBase.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestMapFieldResourceTestBase.php
@@ -82,6 +82,11 @@ protected function getExpectedNormalizedEntity() {
           'value' => 'Llama',
         ],
       ],
+      'langcode' => [
+        [
+          'value' => 'en',
+        ],
+      ],
       'created' => [
         $this->formatExpectedTimestampItemValues((int) $this->entity->get('created')->value),
       ],