diff --git a/core/lib/Drupal/Core/Cache/DatabaseBackend.php b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
index 52f7e13866..c5d6a0dc25 100644
--- a/core/lib/Drupal/Core/Cache/DatabaseBackend.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
@@ -81,7 +81,7 @@ class DatabaseBackend implements CacheBackendInterface {
    *   (optional) The maximum number of rows that are allowed in this cache bin
    *   table.
    * @param \Drupal\Component\Serialization\ObjectAwareSerializationInterface $serializer
-   *   The serializer to use.
+   *   (optional) The serializer to use.
    */
   public function __construct(Connection $connection, CacheTagsChecksumInterface $checksum_provider, $bin, $max_rows = NULL, ObjectAwareSerializationInterface $serializer = NULL) {
     // All cache tables should be prefixed with 'cache_'.
@@ -91,13 +91,10 @@ public function __construct(Connection $connection, CacheTagsChecksumInterface $
     $this->connection = $connection;
     $this->checksumProvider = $checksum_provider;
     $this->maxRows = $max_rows === NULL ? static::DEFAULT_MAX_ROWS : $max_rows;
-    if ($serializer) {
-      $this->serializer = $serializer;
-    }
-    else {
-      @trigger_error('The serializer service will be a mandatory parameter in Drupal 9.0.x. See https://www.drupal.org/node/3014688.', E_USER_DEPRECATED);
-      $this->serializer = \Drupal::service('serialization.phpserialize');
+    if (!$serializer) {
+      @trigger_error('Calling DatabaseBackend::__construct() without the $serializer argument is deprecated in drupal:8.8.0. The $serializer argument will be required in drupal:9.0.0. See https://www.drupal.org/node/3014688', E_USER_DEPRECATED);
     }
+    $this->serializer = \Drupal::service('serialization.phpserialize');
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Cache/DatabaseBackendFactory.php b/core/lib/Drupal/Core/Cache/DatabaseBackendFactory.php
index 751f30f014..371227c8bc 100644
--- a/core/lib/Drupal/Core/Cache/DatabaseBackendFactory.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackendFactory.php
@@ -46,7 +46,7 @@ class DatabaseBackendFactory implements CacheFactoryInterface {
    * @param \Drupal\Core\Site\Settings $settings
    *   (optional) The site settings.
    * @param \Drupal\Component\Serialization\ObjectAwareSerializationInterface $serializer
-   *   The serializer to use.
+   *   (optional) The serializer to use.
    *
    * @throws \BadMethodCallException
    */
@@ -54,13 +54,10 @@ public function __construct(Connection $connection, CacheTagsChecksumInterface $
     $this->connection = $connection;
     $this->checksumProvider = $checksum_provider;
     $this->settings = $settings ?: Settings::getInstance();
-    if ($serializer) {
-      $this->serializer = $serializer;
-    }
-    else {
-      @trigger_error('The serializer service will be a mandatory parameter in Drupal 9.0.x. See https://www.drupal.org/node/3014688.', E_USER_DEPRECATED);
-      $this->serializer = \Drupal::service('serialization.phpserialize');
+    if (!$serializer) {
+      @trigger_error('Calling DatabaseBackendFactory::__construct() without the $serializer argument is deprecated in drupal:8.8.0. The $serializer argument will be required in drupal:9.0.0. See https://www.drupal.org/node/3014688', E_USER_DEPRECATED);
     }
+    $this->serializer = \Drupal::service('serialization.phpserialize');
   }
 
   /**
diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index 9cec85d2df..58d67cf00a 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -82,7 +82,13 @@ class DrupalKernel implements DrupalKernelInterface, TerminableInterface {
       ],
       'cache.container' => [
         'class' => 'Drupal\Core\Cache\DatabaseBackend',
-        'arguments' => ['@database', '@cache_tags_provider.container', 'container', DatabaseBackend::MAXIMUM_NONE, '@serialization.phpserialize'],
+        'arguments' => [
+          '@database',
+          '@cache_tags_provider.container',
+          'container',
+          DatabaseBackend::MAXIMUM_NONE,
+          '@serialization.phpserialize',
+        ],
       ],
       'cache_tags_provider.container' => [
         'class' => 'Drupal\Core\Cache\DatabaseCacheTagsChecksum',