diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 0b861c4..e257aa4 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2147,12 +2147,10 @@ function drupal_bootstrap($phase = NULL, $new_phase = TRUE) {
     DRUPAL_BOOTSTRAP_LANGUAGE,
     DRUPAL_BOOTSTRAP_FULL,
   );
-  // Not drupal_static(), because the only legitimate API to control this is to
-  // call drupal_bootstrap() with a new phase parameter.
-  static $final_phase;
-  // Not drupal_static(), because it's impossible to roll back to an earlier
-  // bootstrap state.
-  static $stored_phase = -1;
+  // drupal_static(), since tests need to be able to re-bootstrap Drupal from an
+  // almost clean slate.
+  $final_phase = &drupal_static('bootstrap:final');
+  $stored_phase = &drupal_static('bootstrap:last', -1);
 
   // When not recursing, store the phase name so it's not forgotten while
   // recursing.
diff --git a/core/modules/simpletest/drupal_web_test_case.php b/core/modules/simpletest/drupal_web_test_case.php
index a5fb606..b7a914b 100644
--- a/core/modules/simpletest/drupal_web_test_case.php
+++ b/core/modules/simpletest/drupal_web_test_case.php
@@ -1400,9 +1400,15 @@ class DrupalWebTestCase extends DrupalTestCase {
       module_enable(array($this->profile), FALSE);
     }
 
+    debug(drupal_static('file_get_stream_wrappers'));
     // Reset/rebuild all data structures after enabling the modules.
+//    system_rebuild_module_data();
     $this->resetAll();
 
+    // Bootstrap into test environment.
+    drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
+    debug(drupal_static('file_get_stream_wrappers'));
+
     // Run cron once in that environment, as install.php does at the end of
     // the installation process.
     drupal_cron_run();
diff --git a/core/modules/simpletest/tests/file.test b/core/modules/simpletest/tests/file.test
index 7496902..3a73c08 100644
--- a/core/modules/simpletest/tests/file.test
+++ b/core/modules/simpletest/tests/file.test
@@ -47,6 +47,8 @@ function file_test_file_scan_callback_reset() {
  * assertions and helper functions.
  */
 class FileTestCase extends DrupalWebTestCase {
+  protected $profile = 'testing';
+
   /**
    * Check that two files have the same values for all fields other than the
    * timestamp.