diff --git a/modules/simpletest/drupal_web_test_case.php b/modules/simpletest/drupal_web_test_case.php
index 694880b..2c32917 100644
--- a/modules/simpletest/drupal_web_test_case.php
+++ b/modules/simpletest/drupal_web_test_case.php
@@ -447,7 +447,8 @@ 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');
+      $class_safe = str_replace('\\', '-', get_class($this));
+      $url = file_create_url($this->originalFileDirectory . '/simpletest/verbose/' . $class_safe . '-' . $id . '.html');
       $this->error(l(t('Verbose message'), $url, array('attributes' => array('target' => '_blank'))), 'User notice');
     }
   }
@@ -466,7 +467,8 @@ abstract class DrupalTestCase {
    */
   public function run(array $methods = array()) {
     // Initialize verbose debugging.
-    simpletest_verbose(NULL, variable_get('file_public_path', conf_path() . '/files'), get_class($this));
+    $class = get_class($this);
+    simpletest_verbose(NULL, variable_get('file_public_path', conf_path() . '/files'), str_replace('\\', '-', $class));
 
     // HTTP auth settings (<username>:<password>) for the simpletest browser
     // when sending requests to the test site.
@@ -478,7 +480,6 @@ abstract class DrupalTestCase {
     }
 
     set_error_handler(array($this, 'errorHandler'));
-    $class = get_class($this);
     // Iterate through all the methods in this class, unless a specific list of
     // methods to run was passed.
     $class_methods = get_class_methods($class);
diff --git a/modules/simpletest/simpletest.module b/modules/simpletest/simpletest.module
index f825755..7442ea2 100644
--- a/modules/simpletest/simpletest.module
+++ b/modules/simpletest/simpletest.module
@@ -157,6 +157,7 @@ function simpletest_run_tests($test_list, $reporter = 'drupal') {
  * Batch operation callback.
  */
 function _simpletest_batch_operation($test_list_init, $test_id, &$context) {
+  simpletest_classloader_register();
   // Get working values.
   if (!isset($context['sandbox']['max'])) {
     // First iteration: initialize working values.
@@ -289,6 +290,9 @@ function simpletest_log_read($test_id, $prefix, $test_class, $during_test = FALS
  * a static variable. In order to list tests provided by disabled modules
  * hook_registry_files_alter() is used to forcefully add them to the registry.
  *
+ * PSR-0 classes are found by searching the designated directory for each module
+ * for files matching the PSR-0 standard.
+ *
  * @return
  *   An array of tests keyed with the groups specified in each of the tests
  *   getInfo() method and then keyed by the test class. An example of the array
@@ -309,6 +313,9 @@ function simpletest_test_get_all() {
   $groups = &drupal_static(__FUNCTION__);
 
   if (!$groups) {
+    // Register a simple class loader for PSR-0 test classes.
+    simpletest_classloader_register();
+
     // Load test information from cache if available, otherwise retrieve the
     // information from each tests getInfo() method.
     if ($cache = cache_get('simpletest', 'cache')) {
@@ -318,6 +325,30 @@ function simpletest_test_get_all() {
       // Select all clases in files ending with .test.
       $classes = db_query("SELECT name FROM {registry} WHERE type = :type AND filename LIKE :name", array(':type' => 'class', ':name' => '%.test'))->fetchCol();
 
+      // Select all PSR-0 classes in the Tests namespace of all modules.
+      $system_list = db_query("SELECT name, filename FROM {system}")->fetchAllKeyed();
+
+      foreach ($system_list as $name => $filename) {
+        // Build directory in which the test files would reside.
+        $tests_dir = DRUPAL_ROOT . '/' . dirname($filename) . '/lib/Drupal/' . $name . '/Tests';
+        // Scan it for test files if it exists.
+        if (is_dir($tests_dir)) {
+          $files = file_scan_directory($tests_dir, '/.*\.php/');
+          if (!empty($files)) {
+            $basedir = DRUPAL_ROOT . '/' . dirname($filename) . '/lib/';
+            foreach ($files as $file) {
+              // Convert the file name into the namespaced class name.
+              $replacements = array(
+                '/' => '\\',
+                $basedir => '',
+                '.php' => '',
+              );
+              $classes[] = strtr($file->uri, $replacements);
+            }
+          }
+        }
+      }
+
       // Check that each class has a getInfo() method and store the information
       // in an array keyed with the group specified in the test information.
       $groups = array();
@@ -354,6 +385,42 @@ function simpletest_test_get_all() {
 }
 
 /**
+ * Register a simple class loader that can find D8-style PSR-0 test classes.
+ * Other PSR-0 class loading can happen in contrib, but for test classes we need
+ * to do in core.
+ */
+function simpletest_classloader_register() {
+  spl_autoload_register('_simpletest_autoload');
+}
+
+/**
+ * Autoload callback to find PSR-0 test classes.
+ */
+function _simpletest_autoload($class) {
+  static $extensions;
+  if (substr($class, 0, 7) === 'Drupal\\') {
+    $pos = strpos($class, '\\', 7);
+    if (substr($class, $pos, 7) === '\\Tests\\') {
+      $extension = substr($class, 7, $pos - 7);
+      if (!isset($extensions)) {
+        $extensions = db_query("SELECT name, filename FROM {system}")->fetchAllKeyed();
+      }
+      if (isset($extensions[$extension])) {
+        $nspos = strrpos($class, '\\');
+        $namespace = substr($class, 0, $nspos);
+        $classname = substr($class, $nspos + 1);
+        $path = dirname($extensions[$extension]) . '/lib/' .
+          str_replace('\\', '/', $namespace) . '/' .
+          str_replace('_', '/', $classname) . '.php';
+        if (file_exists($path)) {
+          include $path;
+        }
+      }
+    }
+  }
+}
+
+/**
  * Implements hook_registry_files_alter().
  *
  * Add the test files for disabled modules so that we get a list containing
diff --git a/modules/simpletest/simpletest.pages.inc b/modules/simpletest/simpletest.pages.inc
index d1a7e4a..9302fa2 100644
--- a/modules/simpletest/simpletest.pages.inc
+++ b/modules/simpletest/simpletest.pages.inc
@@ -181,8 +181,10 @@ function theme_simpletest_test_table($variables) {
  * Run selected tests.
  */
 function simpletest_test_form_submit($form, &$form_state) {
+  simpletest_classloader_register();
   // Get list of tests.
   $tests_list = array();
+  simpletest_classloader_register();
   foreach ($form_state['values'] as $class_name => $value) {
     // Since class_exists() will likely trigger an autoload lookup,
     // we do the fast check first.
@@ -233,6 +235,8 @@ function simpletest_result_form($form, &$form_state, $test_id) {
     '#debug' => 0,
   );
 
+  simpletest_classloader_register();
+
   // Cycle through each test group.
   $header = array(t('Message'), t('Group'), t('Filename'), t('Line'), t('Function'), array('colspan' => 2, 'data' => t('Status')));
   $form['result']['results'] = array();
diff --git a/scripts/run-tests.sh b/scripts/run-tests.sh
index 3345015..1aef28f 100755
--- a/scripts/run-tests.sh
+++ b/scripts/run-tests.sh
@@ -395,7 +395,7 @@ function simpletest_script_command($test_id, $test_class) {
   if ($args['color']) {
     $command .= ' --color';
   }
-  $command .= " --php " . escapeshellarg($php) . " --test-id $test_id --execute-test $test_class";
+  $command .= " --php " . escapeshellarg($php) . " --test-id $test_id --execute-test " . escapeshellarg($test_class);
   return $command;
 }