diff --git a/core/modules/locale/lib/Drupal/locale/LocaleTranslation.php b/core/modules/locale/lib/Drupal/locale/LocaleTranslation.php
index 6bcda02..e6a7ac9 100644
--- a/core/modules/locale/lib/Drupal/locale/LocaleTranslation.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleTranslation.php
@@ -122,7 +122,7 @@ protected function canTranslateEnglish() {
    * {@inheritdoc}
    */
   public function reset() {
-    $this->translateEnglish = NULL;
+    unset($this->translateEnglish);
     $this->translations = array();
   }