diff --git a/modules/simpletest/drupal_web_test_case.php b/modules/simpletest/drupal_web_test_case.php
index d83dbeb..1542ac4 100644
--- a/modules/simpletest/drupal_web_test_case.php
+++ b/modules/simpletest/drupal_web_test_case.php
@@ -448,7 +448,10 @@ abstract class DrupalTestCase {
   protected function verbose($message) {
     if ($id = simpletest_verbose($message)) {
       $url = file_create_url($this->originalFileDirectory . '/simpletest/verbose/' . get_class($this) . '-' . $id . '.html');
-      $this->error(l(t('Verbose message'), $url, array('attributes' => array('target' => '_blank'))), 'User notice');
+      // Not using l() to avoid invoking the theme system, so that unit tests
+      // can use verbose() as well.
+      $url = '<a href="' . $url . '" target="_blank">' . t('Verbose message') . '</a>';
+      $this->error($url, 'User notice');
     }
   }