diff --git a/core/modules/rest/tests/src/Functional/BcTimestampNormalizerUnixTestTrait.php b/core/modules/rest/tests/src/Functional/BcTimestampNormalizerUnixTestTrait.php
index b7717c0..a275f64 100644
--- a/core/modules/rest/tests/src/Functional/BcTimestampNormalizerUnixTestTrait.php
+++ b/core/modules/rest/tests/src/Functional/BcTimestampNormalizerUnixTestTrait.php
@@ -24,7 +24,7 @@
   protected function formatExpectedTimestampItemValues($timestamp) {
     // If the setting is enabled, just return the timestamp as-is now.
     if ($this->config('serialization.settings')->get('bc_timestamp_normalizer_unix')) {
-      return ['value' => (int) $timestamp];
+      return ['value' => $timestamp];
     }
 
     // Otherwise, format the date string to the same that
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/File/FileResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/File/FileResourceTestBase.php
index 4093c05..1815dc7 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/File/FileResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/File/FileResourceTestBase.php
@@ -84,7 +84,7 @@ protected function getExpectedNormalizedEntity() {
         $this->formatExpectedTimestampItemValues($this->entity->getChangedTime()),
       ],
       'created' => [
-        $this->formatExpectedTimestampItemValues($this->entity->getCreatedTime()),
+        $this->formatExpectedTimestampItemValues((int) $this->entity->getCreatedTime()),
       ],
       'fid' => [
         [