diff --git a/core/lib/Drupal/Core/Extension/ModuleInstaller.php b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
index 7bf6994..2d4d803 100644
--- a/core/lib/Drupal/Core/Extension/ModuleInstaller.php
+++ b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
@@ -11,6 +11,12 @@
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\DrupalKernelInterface;
 
+/**
+ * Default implementation of the module installer.
+ *
+ * It registers the module in config, install its own configuration,
+ * installs the schema, updates the Drupal kernel and more.
+ */
 class ModuleInstaller implements ModuleInstallerInterface {
 
   /**
@@ -112,7 +118,7 @@ public function install(array $module_list, $enable_dependencies = TRUE) {
         // different from the configured list of enabled modules. For all active
         // modules not contained in the configured enabled modules, we assume a
         // weight of 0.
-        $current_module_filenames = $this->getModuleList();
+        $current_module_filenames = $this->moduleHandler->getModuleList();
         $current_modules = array_fill_keys(array_keys($current_module_filenames), 0);
         $current_modules = module_config_sort(array_merge($current_modules, $extension_config->get('module')));
         $module_filenames = array();
diff --git a/core/lib/Drupal/Core/Extension/ModuleInstallerInterface.php b/core/lib/Drupal/Core/Extension/ModuleInstallerInterface.php
index 869a2a8..7ab9377 100644
--- a/core/lib/Drupal/Core/Extension/ModuleInstallerInterface.php
+++ b/core/lib/Drupal/Core/Extension/ModuleInstallerInterface.php
@@ -7,6 +7,9 @@
 
 namespace Drupal\Core\Extension;
 
+/**
+ * Provides the installation of modules with creating the db schema and more.
+ */
 interface ModuleInstallerInterface {
 
   /**
diff --git a/core/modules/system/src/Form/ModulesUninstallConfirmForm.php b/core/modules/system/src/Form/ModulesUninstallConfirmForm.php
index 2e5c60e..dccdad8 100644
--- a/core/modules/system/src/Form/ModulesUninstallConfirmForm.php
+++ b/core/modules/system/src/Form/ModulesUninstallConfirmForm.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Config\ConfigManagerInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Extension\ModuleInstallerInterface;
 use Drupal\Core\Form\ConfirmFormBase;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Url;
@@ -69,7 +70,7 @@ class ModulesUninstallConfirmForm extends ConfirmFormBase {
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
    */
-  public function __construct(ModuleHandlerInterface $module_installer, KeyValueStoreExpirableInterface $key_value_expirable, ConfigManagerInterface $config_manager, EntityManagerInterface $entity_manager) {
+  public function __construct(ModuleInstallerInterface $module_installer, KeyValueStoreExpirableInterface $key_value_expirable, ConfigManagerInterface $config_manager, EntityManagerInterface $entity_manager) {
     $this->moduleInstaller = $module_installer;
     $this->keyValueExpirable = $key_value_expirable;
     $this->configManager = $config_manager;