diff --git a/core/lib/Drupal/Core/StringTranslation/TranslationManager.php b/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
index a8d1eb3..872d57f 100644
--- a/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
+++ b/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
@@ -135,7 +135,7 @@ public function translateString(TranslatableMarkup $translated_string) {
    */
   protected function doTranslate($string, array $options = array()) {
     // If a NULL langcode has been provided, unset it.
-    if (array_key_exists('langcode', $options) && $options['langcode'] === NULL) {
+    if (!isset($options['langcode']) && array_key_exists('langcode', $options)) {
       unset($options['langcode']);
     }