diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index f1dd082..d96f3e1 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -959,6 +959,10 @@ protected function resetAll() {
     // Reset static variables and reload permissions.
     $this->refreshVariables();
     $this->checkPermissions(array(), TRUE);
+
+    // Make sure the url generator has a request object, otherwise calls to
+    // $this->drupalGet() will fail.
+    $this->prepareRequestForGenerator();
   }
 
   /**