.../Functional/EntityResource/Comment/CommentResourceTestBase.php   | 2 +-
 .../EntityResource/EntityTest/EntityTestResourceTestBase.php        | 6 +++++-
 .../EntityTestLabel/EntityTestLabelResourceTestBase.php             | 6 +++++-
 .../Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php | 6 +++++-
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
index 7b65c84..ea705de 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
@@ -219,7 +219,7 @@ protected function getNormalizedPostEntity() {
       ],
       'entity_id' => [
         [
-          'target_id' => EntityTest::load(1)->id(),
+          'target_id' => (int) EntityTest::load(1)->id(),
         ],
       ],
       'field_name' => [
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestResourceTestBase.php
index 204c7ff..e2c0ccd 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestResourceTestBase.php
@@ -116,7 +116,11 @@ protected function getExpectedNormalizedEntity() {
    */
   protected function getNormalizedPostEntity() {
     return [
-      'type' => 'entity_test',
+      'type' => [
+        [
+          'value' => 'entity_test',
+        ],
+      ],
       'name' => [
         [
           'value' => 'Dramallama',
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelResourceTestBase.php
index 26d0eca..2257d6c 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelResourceTestBase.php
@@ -117,7 +117,11 @@ protected function getExpectedNormalizedEntity() {
    */
   protected function getNormalizedPostEntity() {
     return [
-      'type' => 'entity_test_label',
+      'type' => [
+        [
+          'value' => 'entity_test_label',
+        ],
+      ],
       'name' => [
         [
           'value' => 'label_llama',
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php
index fb8ebaa..36be5b5 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php
@@ -132,7 +132,11 @@ protected function getNormalizedPostEntity() {
           'uri' => 'internal:/',
         ],
       ],
-      'shortcut_set' => 'default',
+      'shortcut_set' => [
+        [
+          'target_id' => 'default',
+        ],
+      ],
     ];
   }