diff --git a/core/lib/Drupal/Core/StringTranslation/TranslationManager.php b/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
index e9962d6..a8d1eb3 100644
--- a/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
+++ b/core/lib/Drupal/Core/StringTranslation/TranslationManager.php
@@ -134,6 +134,11 @@ public function translateString(TranslatableMarkup $translated_string) {
    *   The translated string.
    */
   protected function doTranslate($string, array $options = array()) {
+    // If a NULL langcode has been provided, unset it.
+    if (array_key_exists('langcode', $options) && $options['langcode'] === NULL) {
+      unset($options['langcode']);
+    }
+
     // Merge in options defaults.
     $options = $options + [
       'langcode' => $this->defaultLangcode,