core/modules/dblog/tests/src/Functional/DbLogResourceTest.php  |  2 +-
 .../Functional/EntityResource/Media/MediaResourceTestBase.php  | 10 ++++++++--
 .../Functional/EntityResource/WorkspaceResourceTestBase.php    | 10 ++++++++--
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/core/modules/dblog/tests/src/Functional/DbLogResourceTest.php b/core/modules/dblog/tests/src/Functional/DbLogResourceTest.php
index 0d46303..36ce50b 100644
--- a/core/modules/dblog/tests/src/Functional/DbLogResourceTest.php
+++ b/core/modules/dblog/tests/src/Functional/DbLogResourceTest.php
@@ -73,7 +73,7 @@ public function testWatchdog() {
     $this->setUpAuthorization('GET');
 
     $response = $this->request('GET', $url, $request_options);
-    $this->assertResourceResponse(200, FALSE, $response, ['config:rest.resource.dblog', 'config:rest.settings', 'http_response'], ['user.permissions'], FALSE, 'MISS');
+    $this->assertResourceResponse(200, FALSE, $response, ['config:rest.resource.dblog', 'http_response'], ['user.permissions'], FALSE, 'MISS');
     $log = Json::decode((string) $response->getBody());
     $this->assertEqual($log['wid'], $id, 'Log ID is correct.');
     $this->assertEqual($log['type'], 'rest', 'Type of log message is correct.');
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
index 127b3da..f46319a 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
@@ -413,10 +413,16 @@ protected function getExpectedNormalizedFileEntity() {
         ],
       ],
       'created' => [
-        $this->formatExpectedTimestampItemValues($file->getCreatedTime()),
+        [
+          'value' => (new \DateTime())->setTimestamp($file->getCreatedTime())->setTimezone(new \DateTimeZone('UTC'))->format(\DateTime::RFC3339),
+          'format' => \DateTime::RFC3339,
+        ],
       ],
       'changed' => [
-        $this->formatExpectedTimestampItemValues($file->getChangedTime()),
+        [
+          'value' => (new \DateTime())->setTimestamp($file->getChangedTime())->setTimezone(new \DateTimeZone('UTC'))->format(\DateTime::RFC3339),
+          'format' => \DateTime::RFC3339,
+        ],
       ],
     ];
   }
diff --git a/core/modules/workspace/tests/src/Functional/EntityResource/WorkspaceResourceTestBase.php b/core/modules/workspace/tests/src/Functional/EntityResource/WorkspaceResourceTestBase.php
index 18ba2dd..8241483 100644
--- a/core/modules/workspace/tests/src/Functional/EntityResource/WorkspaceResourceTestBase.php
+++ b/core/modules/workspace/tests/src/Functional/EntityResource/WorkspaceResourceTestBase.php
@@ -87,10 +87,16 @@ protected function getExpectedNormalizedEntity() {
     $author = User::load($this->entity->getOwnerId());
     return [
       'created' => [
-        $this->formatExpectedTimestampItemValues((int) $this->entity->getCreatedTime()),
+        [
+          'value' => (new \DateTime())->setTimestamp((int) $this->entity->getCreatedTime())->setTimezone(new \DateTimeZone('UTC'))->format(\DateTime::RFC3339),
+          'format' => \DateTime::RFC3339,
+        ],
       ],
       'changed' => [
-        $this->formatExpectedTimestampItemValues($this->entity->getChangedTime()),
+        [
+          'value' => (new \DateTime())->setTimestamp($this->entity->getChangedTime())->setTimezone(new \DateTimeZone('UTC'))->format(\DateTime::RFC3339),
+          'format' => \DateTime::RFC3339,
+        ],
       ],
       'id' => [
         [