diff --git a/core/authorize.php b/core/authorize.php
index d814ba3..9cdb570 100644
--- a/core/authorize.php
+++ b/core/authorize.php
@@ -78,8 +78,8 @@ function authorize_access_allowed() {
 
 // We have to enable the user and system modules, even to check access and
 // display errors via the maintenance theme.
-$module_list['system']['filename'] = 'core/modules/system/system.module';
-$module_list['user']['filename'] = 'core/modules/user/user.module';
+$module_list['system'] = 'core/modules/system/system.module';
+$module_list['user'] = 'core/modules/user/user.module';
 drupal_container()->get('extension_handler')->setModuleList($module_list);
 drupal_container()->get('extension_handler')->load('system');
 drupal_container()->get('extension_handler')->load('user');
diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index f3f2c40..0cdedb9 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -1146,7 +1146,7 @@ function bootstrap_invoke_all($hook) {
  *   TRUE if the item is loaded or has already been loaded.
  */
 function drupal_load($type, $name) {
-  if ($type == 'module') {
+  if ($type == 'module' && drupal_container()->get('extension_handler')->moduleExists($name)) {
     return drupal_container()->get('extension_handler')->load($name);
   }
 
diff --git a/core/includes/module.inc b/core/includes/module.inc
index 5e2f1b9..3f9de34 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -456,6 +456,10 @@ function module_disable($module_list, $disable_dependents = TRUE) {
   }
 
   if (!empty($invoke_modules)) {
+    // Refresh the system list to exclude the disabled modules.
+    // @todo This call is only needed so that the theme info gets rebuilt - see
+    //   the todo in system_list_reset().
+    system_list_reset();
     // Refresh the module list to exclude the disabled modules.
     drupal_container()->get('extension_handler')->moduleImplementsReset();
     entity_info_cache_clear();
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/MainContentFallbackTest.php b/core/modules/system/lib/Drupal/system/Tests/System/MainContentFallbackTest.php
index 2de5ad3..d83bdc3 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/MainContentFallbackTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/MainContentFallbackTest.php
@@ -55,8 +55,8 @@ function testMainContentFallback() {
     // Disable the block module.
     $edit['modules[Core][block][enable]'] = FALSE;
     $this->drupalPost('admin/modules', $edit, t('Save configuration'));
+    $this->rebuildContainer();
     $this->assertText(t('The configuration options have been saved.'), 'Modules status has been updated.');
-    system_list_reset();
     $this->assertFalse(module_exists('block'), 'Block module disabled.');
 
     // At this point, no region is filled and fallback should be triggered.
@@ -89,8 +89,8 @@ function testMainContentFallback() {
     $edit = array();
     $edit['modules[Core][block][enable]'] = 'block';
     $this->drupalPost('admin/modules', $edit, t('Save configuration'));
+    $this->rebuildContainer();
     $this->assertText(t('The configuration options have been saved.'), 'Modules status has been updated.');
-    system_list_reset();
     $this->assertTrue(module_exists('block'), 'Block module re-enabled.');
   }
 }