diff --git a/core/includes/common.inc b/core/includes/common.inc
index ba508fd31da..7ba47fba679 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -5174,7 +5174,7 @@ function drupal_system_listing($mask, $directory, $key = 'name', $min_depth = 1)
   // distribution we need to include the profile of the parent site (in which
   // test runs are triggered).
   if (drupal_valid_test_ua()) {
-    $testing_profile = config('simpletest.settings')->get('parent_profile');
+    $testing_profile = variable_get('simpletest_parent_profile', FALSE);
     if ($testing_profile && $testing_profile != $profile) {
       $profiles[] = $testing_profile;
     }
diff --git a/core/modules/simpletest/config/simpletest.settings.yml b/core/modules/simpletest/config/simpletest.settings.yml
deleted file mode 100644
index 1fe90563844..00000000000
--- a/core/modules/simpletest/config/simpletest.settings.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-clear_results: '1'
-httpauth:
-    method: '1'
-    password: ''
-    username: ''
-maximum_redirects: '5'
-parent_profile: ''
-verbose: '1'
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index a9c4c41eb3f..cccd0112f7d 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -529,10 +529,8 @@ abstract class TestBase {
    *   methods during debugging.
    */
   public function run(array $methods = array()) {
-    $simpletest_config = config('simpletest.settings');
-
     $class = get_class($this);
-    if ($simpletest_config->get('verbose')) {
+    if (variable_get('simpletest_verbose', TRUE)) {
       // Initialize verbose debugging.
       $this->verbose = TRUE;
       $this->verboseDirectory = variable_get('file_public_path', conf_path() . '/files') . '/simpletest/verbose';
@@ -543,16 +541,13 @@ abstract class TestBase {
     }
     // HTTP auth settings (<username>:<password>) for the simpletest browser
     // when sending requests to the test site.
-    $this->httpauth_method = (int) $simpletest_config->get('httpauth.method');
-    $username = $simpletest_config->get('httpauth.username');
-    $password = $simpletest_config->get('httpauth.password');
-    if (!empty($username) && !empty($password)) {
+    $this->httpauth_method = variable_get('simpletest_httpauth_method', CURLAUTH_BASIC);
+    $username = variable_get('simpletest_httpauth_username', NULL);
+    $password = variable_get('simpletest_httpauth_password', NULL);
+    if ($username && $password) {
       $this->httpauth_credentials = $username . ':' . $password;
     }
 
-    // Maximum redirects setting for the simpletest browser.
-    $this->maximumRedirects = $simpletest_config->get('maximum_redirects');
-
     set_error_handler(array($this, 'errorHandler'));
     // Iterate through all the methods in this class, unless a specific list of
     // methods to run was passed.
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php b/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php
index 7fddae43bdd..938054a75b6 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php
@@ -76,7 +76,7 @@ class SimpleTestTest extends WebTestBase {
         'name' => $user->name,
         'pass' => $user->pass_raw
       );
-      $this->maximumRedirects = 1;
+      variable_set('simpletest_maximum_redirects', 1);
       $this->drupalPost('user', $edit, t('Log in'), array(
         'query' => array('destination' => 'user/logout'),
       ));
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 481f79fb845..eda23657bd1 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -621,11 +621,11 @@ abstract class WebTestBase extends TestBase {
     variable_set('file_private_path', $this->private_files_directory);
     variable_set('file_temporary_path', $this->temp_files_directory);
 
-    // Set 'parent_profile' of simpletest to add the parent profile's
+    // Set the 'simpletest_parent_profile' variable to add the parent profile's
     // search path to the child site's search paths.
     // @see drupal_system_listing()
     // @todo This may need to be primed like 'install_profile' above.
-    config('simpletest.settings')->set('parent_profile', $this->originalProfile)->save();
+    variable_set('simpletest_parent_profile', $this->originalProfile);
 
     // Include the testing profile.
     variable_set('install_profile', $this->profile);
@@ -917,7 +917,7 @@ abstract class WebTestBase extends TestBase {
     // to prevent fragments being sent to the web server as part
     // of the request.
     // TODO: Remove this for Drupal 8, since fixed in curl 7.20.0.
-    if (in_array($status, array(300, 301, 302, 303, 305, 307)) && $this->redirect_count < $this->maximumRedirects) {
+    if (in_array($status, array(300, 301, 302, 303, 305, 307)) && $this->redirect_count < variable_get('simpletest_maximum_redirects', 5)) {
       if ($this->drupalGetHeader('location')) {
         $this->redirect_count++;
         $curl_options = array();
diff --git a/core/modules/simpletest/simpletest.install b/core/modules/simpletest/simpletest.install
index 821a0db9f3e..23db4dc7f67 100644
--- a/core/modules/simpletest/simpletest.install
+++ b/core/modules/simpletest/simpletest.install
@@ -170,21 +170,13 @@ function simpletest_uninstall() {
   drupal_load('module', 'simpletest');
   simpletest_clean_database();
 
+  // Remove settings variables.
+  variable_del('simpletest_httpauth_method');
+  variable_del('simpletest_httpauth_username');
+  variable_del('simpletest_httpauth_password');
+  variable_del('simpletest_clear_results');
+  variable_del('simpletest_verbose');
+
   // Remove generated files.
   file_unmanaged_delete_recursive('public://simpletest');
 }
-
-/**
- * Move simpletest settings from variables to config.
- */
-function simpletest_update_8000() {
-  update_variables_to_config('simpletest.settings', array(
-    'simpletest_clear_results' => 'clear_results',
-    'simpletest_httpauth_method' => 'httpauth.method',
-    'simpletest_httpauth_password' => 'httpauth.password',
-    'simpletest_httpauth_username' => 'httpauth.username',
-    'simpletest_maximum_redirects' => 'maximum_redirects',
-    'simpletest_parent_profile' => 'parent_profile',
-    'simpletest_verbose' => 'verbose',
-  ));
-}
diff --git a/core/modules/simpletest/simpletest.module b/core/modules/simpletest/simpletest.module
index 0fd025e3293..413891695fc 100644
--- a/core/modules/simpletest/simpletest.module
+++ b/core/modules/simpletest/simpletest.module
@@ -460,7 +460,7 @@ function simpletest_generate_file($filename, $width, $lines, $type = 'binary-tex
 function simpletest_clean_environment() {
   simpletest_clean_database();
   simpletest_clean_temporary_directories();
-  if (config('simpletest.settings')->get('clear_results')) {
+  if (variable_get('simpletest_clear_results', TRUE)) {
     $count = simpletest_clean_results_table();
     drupal_set_message(format_plural($count, 'Removed 1 test result.', 'Removed @count test results.'));
   }
@@ -530,7 +530,7 @@ function simpletest_clean_temporary_directories() {
  *   The number of results removed.
  */
 function simpletest_clean_results_table($test_id = NULL) {
-  if (config('simpletest.settings')->get('clear_results')) {
+  if (variable_get('simpletest_clear_results', TRUE)) {
     if ($test_id) {
       $count = db_query('SELECT COUNT(test_id) FROM {simpletest_test_id} WHERE test_id = :test_id', array(':test_id' => $test_id))->fetchField();
 
diff --git a/core/modules/simpletest/simpletest.pages.inc b/core/modules/simpletest/simpletest.pages.inc
index 8b8ee74a4c4..a98b445548d 100644
--- a/core/modules/simpletest/simpletest.pages.inc
+++ b/core/modules/simpletest/simpletest.pages.inc
@@ -434,10 +434,8 @@ function simpletest_result_status_image($status) {
  *
  * @ingroup forms
  * @see simpletest_settings_form_validate()
- * @see simpletest_settings_form_submit()
  */
 function simpletest_settings_form($form, &$form_state) {
-  $config = config('simpletest.settings');
   $form['general'] = array(
     '#type' => 'fieldset',
     '#title' => t('General'),
@@ -446,13 +444,13 @@ function simpletest_settings_form($form, &$form_state) {
     '#type' => 'checkbox',
     '#title' => t('Clear results after each complete test suite run'),
     '#description' => t('By default SimpleTest will clear the results after they have been viewed on the results page, but in some cases it may be useful to leave the results in the database. The results can then be viewed at <em>admin/config/development/testing/[test_id]</em>. The test ID can be found in the database, simpletest table, or kept track of when viewing the results the first time. Additionally, some modules may provide more analysis or features that require this setting to be disabled.'),
-    '#default_value' => $config->get('clear_results'),
+    '#default_value' => variable_get('simpletest_clear_results', TRUE),
   );
   $form['general']['simpletest_verbose'] = array(
     '#type' => 'checkbox',
     '#title' => t('Provide verbose information when running tests'),
     '#description' => t('The verbose data will be printed along with the standard assertions and is useful for debugging. The verbose data will be erased between each test suite run. The verbose data output is very detailed and should only be used when debugging.'),
-    '#default_value' => $config->get('verbose'),
+    '#default_value' => variable_get('simpletest_verbose', TRUE),
   );
 
   $form['httpauth'] = array(
@@ -473,16 +471,16 @@ function simpletest_settings_form($form, &$form_state) {
       CURLAUTH_ANY => t('Any'),
       CURLAUTH_ANYSAFE => t('Any safe'),
     ),
-    '#default_value' => $config->get('httpauth.method'),
+    '#default_value' => variable_get('simpletest_httpauth_method', CURLAUTH_BASIC),
   );
-  $username = $config->get('httpauth.username');
-  $password = $config->get('httpauth.password');
+  $username = variable_get('simpletest_httpauth_username');
+  $password = variable_get('simpletest_httpauth_password');
   $form['httpauth']['simpletest_httpauth_username'] = array(
     '#type' => 'textfield',
     '#title' => t('Username'),
     '#default_value' => $username,
   );
-  if (!empty($username) && !empty($password)) {
+  if ($username && $password) {
     $form['httpauth']['simpletest_httpauth_username']['#description'] = t('Leave this blank to delete both the existing username and password.');
   }
   $form['httpauth']['simpletest_httpauth_password'] = array(
@@ -493,20 +491,7 @@ function simpletest_settings_form($form, &$form_state) {
     $form['httpauth']['simpletest_httpauth_password']['#description'] = t('To change the password, enter the new password here.');
   }
 
-  return system_config_form($form, $form_state);
-}
-
-/**
- * Form submission handler for simpletest_settings_form().
- */
-function simpletest_settings_form_submit($form, &$form_state) {
-  config('simpletest.settings')
-    ->set('clear_results', $form_state['values']['simpletest_clear_results'])
-    ->set('verbose', $form_state['values']['simpletest_verbose'])
-    ->set('httpauth.method', $form_state['values']['simpletest_httpauth_method'])
-    ->set('httpauth.username', $form_state['values']['simpletest_httpauth_username'])
-    ->set('httpauth.password', $form_state['values']['simpletest_httpauth_password'])
-    ->save();
+  return system_settings_form($form);
 }
 
 /**
@@ -516,7 +501,7 @@ function simpletest_settings_form_validate($form, &$form_state) {
   // If a username was provided but a password wasn't, preserve the existing
   // password.
   if (!empty($form_state['values']['simpletest_httpauth_username']) && empty($form_state['values']['simpletest_httpauth_password'])) {
-    $form_state['values']['simpletest_httpauth_password'] = config('simpletest.settings')->get('httpauth.password');
+    $form_state['values']['simpletest_httpauth_password'] = variable_get('simpletest_httpauth_password', '');
   }
 
   // If a password was provided but a username wasn't, the credentials are