diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 8a6a365..fa07559 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2660,7 +2660,14 @@ function drupal_language_initialize() {
  *   The type of language object needed, e.g. LANGUAGE_TYPE_INTERFACE.
  */
 function language($type) {
-  return drupal_container()->get('language_manager')->getLanguage($type);
+  $container = drupal_container();
+  if (!$container->has('language_manager')) {
+    // This happens in rare situations when the container has not been built by
+    // a kernel and has no services e.g. when t() is called during unit tests for
+    // assertions.
+    $container->register('language_manager', 'Drupal\Core\Language\LanguageManager');
+  }
+  return $container->get('language_manager')->getLanguage($type);
 }
 
 /**