diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index 2e8b127..370cfba 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -531,7 +531,7 @@ public function discoverServiceProviders() {
       }
     }
     if (!$this->addServiceFiles(Settings::get('container_yamls'))) {
-      throw new \Exception('"Please add $settings["container_yamls"][] = __DIR__ . "/services.yml"; to settings.php');
+      throw new \Exception('The container_yamls settings is missing.');
     }
   }
 
@@ -1297,7 +1297,8 @@ protected static function setupTrustedHosts(Request $request, $hostPatterns) {
    *
    * @param $service_yamls
    *   A list of service files.
-   * @return
+   *
+   * @return bool
    *   TRUE if the list was an array, FALSE otherwise.
    */
   protected function addServiceFiles($service_yamls) {