diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index 000622c..008ea9d 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -880,7 +880,7 @@ protected function prepareEnvironment() {
     $this->originalConf = $conf;
 
     // Backup statics and globals.
-    $this->originalContainer = clone \Drupal::getContainer;
+    $this->originalContainer = clone \Drupal::getContainer();
     $this->originalLanguage = $language_interface;
     $this->originalConfigDirectories = $GLOBALS['config_directories'];
     if (isset($GLOBALS['theme_key'])) {