Index: modules/simpletest/drupal_test_suite.php
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/drupal_test_suite.php,v
retrieving revision 1.2
diff -u -r1.2 drupal_test_suite.php
--- modules/simpletest/drupal_test_suite.php	23 Apr 2008 17:49:50 -0000	1.2
+++ modules/simpletest/drupal_test_suite.php	27 Apr 2008 05:44:03 -0000
@@ -120,6 +120,13 @@
       if (file_exists($test)) {
         $files[] = $test;
       }
+
+      $tests_directory = $module_path . '/tests';
+      if (is_dir($tests_directory)) {
+        foreach (file_scan_directory($tests_directory, '\.test$') as $file) {
+          $files[] = $file->filename;
+        }
+      }
     }
     return $files;
   }