diff --git a/modules/simpletest/drupal_web_test_case.php b/modules/simpletest/drupal_web_test_case.php
index 9a9c360..194d532 100644
--- a/modules/simpletest/drupal_web_test_case.php
+++ b/modules/simpletest/drupal_web_test_case.php
@@ -407,6 +407,7 @@ abstract class DrupalTestCase {
    * Run all tests in this class.
    */
   public function run() {
+    set_time_limit(0);
     // Initialize verbose debugging.
     simpletest_verbose(NULL, file_directory_path(), get_class($this));