diff --git a/core/includes/module.inc b/core/includes/module.inc
index c7f5d76..f9dd1f7 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -657,11 +657,20 @@ function drupal_required_modules() {
 function module_set_weight($module, $weight) {
   // Update the module weight in the config file that contains it.
   $module_config = config('system.module');
+  $extension_handler = drupal_extension_handler();
+  $enabled_modules = $extension_handler->getEnabledModules();
   if ($module_config->get("enabled.$module") !== NULL) {
+    $sorted_modules = module_config_sort($module_config->get('enabled'));
     $module_config
       ->set("enabled.$module", $weight)
-      ->set('enabled', module_config_sort($module_config->get('enabled')))
+      ->set('enabled', $sorted_modules)
       ->save();
+    $sorted_with_filenames = array();
+    foreach (array_keys($sorted_modules) as $m) {
+      $sorted_with_filenames[$m] = $enabled_modules[$m];
+    }
+    // Refresh the module list in the extension handler.
+    $extension_handler->setModuleList($sorted_with_filenames);
     return;
   }
   $disabled_config = config('system.module.disabled');
diff --git a/core/modules/breakpoint/breakpoint.install b/core/modules/breakpoint/breakpoint.install
index 97a5777..60ba9cf 100644
--- a/core/modules/breakpoint/breakpoint.install
+++ b/core/modules/breakpoint/breakpoint.install
@@ -18,6 +18,5 @@ function breakpoint_enable() {
   _breakpoint_theme_enabled(array_keys($themes));
 
   // Import breakpoints from modules.
-  $modules = module_list();
   _breakpoint_modules_enabled(array_keys(drupal_extension_handler()->getEnabledModules()));
 }
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
index 648aa42..d7bd225 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
@@ -56,9 +56,6 @@ protected function setUp() {
     $conf = array();
     drupal_static_reset();
 
-    // Enforce an empty module list.
-    module_list(NULL, array());
-
     $conf['file_public_path'] = $this->public_files_directory;
 
     // Change the database prefix.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Module/EnableDisableTest.php b/core/modules/system/lib/Drupal/system/Tests/Module/EnableDisableTest.php
index e73ace9..423b582 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Module/EnableDisableTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Module/EnableDisableTest.php
@@ -39,7 +39,7 @@ function testEnableDisable() {
 
     // Remove already enabled modules (via installation profile).
     // @todo Remove this after removing all dependencies from Testing profile.
-    foreach (module_list() as $dependency) {
+    foreach ($this->container->get('extension_handler')->getEnabledModules() as $dependency => $filename) {
       // Exclude required modules. Only installation profile "suggestions" can
       // be disabled and uninstalled.
       if (isset($modules[$dependency])) {
diff --git a/core/modules/system/lib/Drupal/system/Tests/Module/ModuleApiTest.php b/core/modules/system/lib/Drupal/system/Tests/Module/ModuleApiTest.php
index 42924bf..d139123 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Module/ModuleApiTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Module/ModuleApiTest.php
@@ -50,8 +50,7 @@ function testModuleList() {
 
     // Try to mess with the module weights.
     module_set_weight('contact', 20);
-    // Reset the module list.
-    system_list_reset();
+
     // Move contact to the end of the array.
     unset($module_list[array_search('contact', $module_list)]);
     $module_list[] = 'contact';
@@ -59,16 +58,13 @@ function testModuleList() {
 
     // Test the fixed list feature.
     $fixed_list = array(
-      'system' => array('filename' => drupal_get_path('module', 'system')),
-      'menu' => array('filename' => drupal_get_path('module', 'menu')),
+      'system' => 'core/modules/system/system.module',
+      'menu' => 'core/modules/menu/menu.module',
     );
-    module_list(NULL, $fixed_list);
+    $this->container->get('extension_handler')->setModuleList($fixed_list);
     $new_module_list = array_combine(array_keys($fixed_list), array_keys($fixed_list));
     $this->assertModuleList($new_module_list, t('When using a fixed list'));
 
-    // Reset the module list.
-    module_list_reset();
-    $this->assertModuleList($module_list, t('After reset'));
   }
 
   /**
@@ -78,8 +74,9 @@ function testModuleList() {
    *   The expected values, sorted by weight and module name.
    */
   protected function assertModuleList(Array $expected_values, $condition) {
-    $expected_values = array_combine($expected_values, $expected_values);
-    $this->assertEqual($expected_values, module_list(), format_string('@condition: module_list() returns correct results', array('@condition' => $condition)));
+    $expected_values = array_values(array_unique($expected_values));
+    $enabled_modules = array_keys($this->container->get('extension_handler')->getEnabledModules());
+    $this->assertEqual($expected_values, $enabled_modules, format_string('@condition: module_list() returns correct results', array('@condition' => $condition)));
   }
 
   /**
@@ -106,9 +103,9 @@ function testModuleImplements() {
 
     module_load_include('inc', 'module_test', 'module_test.file');
     $modules = module_implements('test_hook');
-    $static = drupal_static('module_implements');
     $this->assertTrue(in_array('module_test', $modules), 'Hook found.');
-    $this->assertEqual($static['test_hook']['module_test'], 'file', 'Include file detected.');
+    $module_implementations = drupal_extension_handler()->cachedHookImplementations();
+    $this->assertEqual($module_implementations['test_hook']['module_test'], 'file', 'Include file detected.');
   }
 
   /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Module/ModuleTestBase.php b/core/modules/system/lib/Drupal/system/Tests/Module/ModuleTestBase.php
index b7fd25c..d8425c1 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Module/ModuleTestBase.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Module/ModuleTestBase.php
@@ -139,7 +139,6 @@ function assertNoModuleConfig($module) {
    *   Expected module state.
    */
   function assertModules(array $modules, $enabled) {
-    system_list_reset();
     foreach ($modules as $module) {
       if ($enabled) {
         $message = 'Module "@module" is enabled.';