diff --git a/review/simpletest/pifr_simpletest.client.inc b/review/simpletest/pifr_simpletest.client.inc
index 1243a40..6cac044 100644
--- a/review/simpletest/pifr_simpletest.client.inc
+++ b/review/simpletest/pifr_simpletest.client.inc
@@ -47,6 +47,11 @@ class pifr_client_review_pifr_simpletest extends pifr_client_review_pifr_drupal
       $this->database->drop_database();
       $this->database->create_database();
 
+      // Run `composer install` within the core directory of Drupal 8 (or greater)
+      if ($this->arguments['drupal.core.version'] >= 8) {
+        $this->exec('cd core; composer install;');
+      }
+
       // Since a database import is being used the username and password must
       // be included in arguments.
       if (empty($this->arguments['drupal.user']) || empty($this->arguments['drupal.pass'])) {