diff --git a/core/lib/Drupal/Core/Render/HtmlResponse.php b/core/lib/Drupal/Core/Render/HtmlResponse.php
index 21a21805fe9..75b8b29ae3a 100644
--- a/core/lib/Drupal/Core/Render/HtmlResponse.php
+++ b/core/lib/Drupal/Core/Render/HtmlResponse.php
@@ -24,7 +24,27 @@ class HtmlResponse extends Response implements CacheableResponseInterface, Attac
   use CacheableResponseTrait;
   use AttachmentsTrait;
 
-  public function __construct($content = '', int $status = 200, array $headers = []) {
+  public function __construct(
+    ?string $content = '',
+    int $status = 200,
+    array $headers = []
+  ) {
+    parent::__construct($this->getMarkup($content), $status, $headers);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setContent($content) {
+    return parent::setContent($this->getMarkup($content));
+  }
+
+  /**
+   * @param mixed $content
+   *
+   * @return array[]|mixed|string
+   */
+  protected function getMarkup($content = '') {
     // A render array can automatically be converted to a string and set the
     // necessary metadata.
     if (is_array($content) && (isset($content['#markup']))) {
@@ -38,8 +58,7 @@ public function __construct($content = '', int $status = 200, array $headers = [
       $this->setAttachments($content['#attached']);
       $content = $content['#markup'];
     }
-
-    parent::__construct($content, $status, $headers);
+    return $content;
   }
 
 }
diff --git a/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php b/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php
index c326859cf29..8a53ff01059 100644
--- a/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php
+++ b/core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php
@@ -140,6 +140,7 @@ public static function getSkippedDeprecations() {
       // Deprecation introduced in Symfony 5
       'Since symfony/dependency-injection 5.1: The signature of method "Symfony\Component\DependencyInjection\Alias::setDeprecated()" requires 3 arguments: "string $package, string $version, string $message", not defining them is deprecated.',
       'Since symfony/dependency-injection 5.1: The signature of method "Symfony\Component\DependencyInjection\Definition::setDeprecated()" requires 3 arguments: "string $package, string $version, string $message", not defining them is deprecated.',
+      'Since symfony/http-foundation 5.1: Retrieving a non-string value from "Symfony\Component\HttpFoundation\InputBag::get()" is deprecated, and will throw a "Symfony\Component\HttpFoundation\Exception\BadRequestException" exception in Symfony 6.0, use "Symfony\Component\HttpFoundation\InputBag::all($key)" instead.'
     ];
 
     // Deprecations introduced in Symfony 5