diff -u b/core/lib/Drupal/Component/Utility/SafeMarkup.php b/core/lib/Drupal/Component/Utility/SafeMarkup.php
--- b/core/lib/Drupal/Component/Utility/SafeMarkup.php
+++ b/core/lib/Drupal/Component/Utility/SafeMarkup.php
@@ -46,7 +46,7 @@
    */
   public static function init() {
     if (!isset(static::$safeStrings)) {
-      static::$safeStrings = &StaticStorage::get(__CLASS__);
+      static::$safeStrings = &StaticStorage::get(__CLASS__, []);
     }
   }