diff --git a/core/includes/module.inc b/core/includes/module.inc
index f65f0b8..84f9125 100644
--- a/core/includes/module.inc
+++ b/core/includes/module.inc
@@ -59,6 +59,7 @@ function system_list($type) {
 function system_list_reset() {
   drupal_static_reset('system_list');
   drupal_static_reset('system_rebuild_module_data');
+  \Drupal::service('module_listing')->reset();
   \Drupal::cache('bootstrap')->delete('system_list');
 }
 
diff --git a/core/lib/Drupal/Core/Extension/ExtensionList.php b/core/lib/Drupal/Core/Extension/ExtensionList.php
index 8b3b47f..2e5aeae 100644
--- a/core/lib/Drupal/Core/Extension/ExtensionList.php
+++ b/core/lib/Drupal/Core/Extension/ExtensionList.php
@@ -56,6 +56,13 @@ class ExtensionList {
   protected $moduleHandler;
 
   /**
+   * The static cached extensions.
+   *
+   * @var \Drupal\Core\Extension\Extension[]
+   */
+  protected $extensions;
+
+  /**
    * Constructs a new ExtensionList instance.
    *
    * @param string $root
@@ -77,6 +84,20 @@ public function __construct($root, $type, StateInterface $state, InfoParserInter
     $this->moduleHandler = $module_handler;
   }
 
+  public function reset() {
+    $this->extensions = NULL;
+    $this->state->delete($this->getStateKey());
+  }
+
+  /**
+   * Returns the used state key.
+   *
+   * @return string
+   */
+  protected function getStateKey() {
+    return 'core.extension_listing.' . $this->type;
+  }
+
   /**
    * Returns the human readable name of the extension.
    *
@@ -95,6 +116,19 @@ public function getName($name) {
   }
 
   /**
+   * Returns a single extension.
+   *
+   * @param string $name
+   *   The extension name.
+   *
+   * @return \Drupal\Core\Extension\Extension
+   */
+  public function getExtension($name) {
+    $extensions = $this->listExtensions();
+    return $extensions[$name];
+  }
+
+  /**
    * Returns all available extensions.
    *
    * @return \Drupal\Core\Extension\Extension[]
@@ -103,11 +137,11 @@ public function listExtensions() {
     if (isset($this->extensions)) {
       return $this->extensions;
     }
-    if ($extensions = $this->state->get('core.extension_listing.' . $this->type)) {
+    if ($extensions = $this->state->get($this->getStateKey())) {
       return $extensions;
     }
     $extensions = $this->doListExtensions();
-    $this->state->get('core.extension_listing.' . $this->type);
+    $this->state->get($this->getStateKey());
     $this->extensions = $extensions;
     return $this->extensions;
   }
diff --git a/core/modules/book/src/Tests/BookUninstallTest.php b/core/modules/book/src/Tests/BookUninstallTest.php
index 317a16a..ab7e065 100644
--- a/core/modules/book/src/Tests/BookUninstallTest.php
+++ b/core/modules/book/src/Tests/BookUninstallTest.php
@@ -44,7 +44,8 @@ protected function setUp() {
    */
   public function testBookUninstall() {
     // No nodes exist.
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertFalse(isset($module_data['book']->info['required']), 'The book module is not required.');
 
     $content_type = NodeType::create(array(
@@ -62,7 +63,8 @@ public function testBookUninstall() {
     $node->save();
 
     // One node in a book but not of type book.
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertTrue($module_data['book']->info['required'], 'The book module is required.');
     $this->assertEqual($module_data['book']->info['explanation'], t('To uninstall Book, delete all content that is part of a book.'));
 
@@ -72,26 +74,30 @@ public function testBookUninstall() {
 
     // Two nodes, one in a book but not of type book and one book node (which is
     // not in a book).
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertTrue($module_data['book']->info['required'], 'The book module is required.');
     $this->assertEqual($module_data['book']->info['explanation'], t('To uninstall Book, delete all content that is part of a book.'));
 
     $node->delete();
     // One node of type book but not actually part of a book.
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertTrue($module_data['book']->info['required'], 'The book module is required.');
     $this->assertEqual($module_data['book']->info['explanation'], t('To uninstall Book, delete all content that has the Book content type.'));
 
     $book_node->delete();
     // No nodes exist therefore the book module is not required.
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertFalse(isset($module_data['book']->info['required']), 'The book module is not required.');
 
     $node = Node::create(array('type' => $content_type->id()));
     $node->save();
     // One node exists but is not part of a book therefore the book module is
     // not required.
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertFalse(isset($module_data['book']->info['required']), 'The book module is not required.');
 
     // Uninstall the Book module and check the node type is deleted.
diff --git a/core/modules/filter/src/Tests/FilterAPITest.php b/core/modules/filter/src/Tests/FilterAPITest.php
index 49b99d2..0386e7d 100644
--- a/core/modules/filter/src/Tests/FilterAPITest.php
+++ b/core/modules/filter/src/Tests/FilterAPITest.php
@@ -424,7 +424,8 @@ public function testDependencyRemoval() {
     ];
     $filter_format->setFilterConfig('filter_test_restrict_tags_and_attributes', $filter_config)->save();
 
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertTrue($module_data['filter_test']->info['required'], 'The filter_test module is required.');
     $this->assertEqual($module_data['filter_test']->info['explanation'], SafeMarkup::format('Provides a filter plugin that is in use in the following filter formats: %formats', array('%formats' => $filter_format->label())));
 
@@ -443,7 +444,8 @@ public function testDependencyRemoval() {
 
     drupal_static_reset('filter_formats');
     \Drupal::entityManager()->getStorage('filter_format')->resetCache();
-    $module_data = _system_rebuild_module_data();
+    \Drupal::service('module_listing')->reset();
+    $module_data = \Drupal::service('module_listing')->listExtensions();
     $this->assertFalse(isset($module_data['filter_test']->info['required']), 'The filter_test module is required.');
 
     // Verify that a dependency exists on the module that provides the filter
diff --git a/core/modules/system/src/Tests/Extension/ModuleHandlerTest.php b/core/modules/system/src/Tests/Extension/ModuleHandlerTest.php
index d2d6fed..edaf2a0 100644
--- a/core/modules/system/src/Tests/Extension/ModuleHandlerTest.php
+++ b/core/modules/system/src/Tests/Extension/ModuleHandlerTest.php
@@ -115,6 +115,7 @@ function testDependencyResolution() {
     // Nothing should be installed.
     \Drupal::state()->set('module_test.dependency', 'missing dependency');
     drupal_static_reset('system_rebuild_module_data');
+    \Drupal::service('module_listing')->reset();
 
     try {
       $result = $this->moduleInstaller()->install(array('color'));
@@ -130,6 +131,7 @@ function testDependencyResolution() {
     // Color module depends on Config. Config depends on Help module.
     \Drupal::state()->set('module_test.dependency', 'dependency');
     drupal_static_reset('system_rebuild_module_data');
+    \Drupal::service('module_listing')->reset();
 
     $result = $this->moduleInstaller()->install(array('color'));
     $this->assertTrue($result, 'ModuleHandler::install() returns the correct value.');
@@ -162,6 +164,7 @@ function testDependencyResolution() {
     // sure that Drupal\Core\Extension\ModuleHandler::install() still works.
     \Drupal::state()->set('module_test.dependency', 'version dependency');
     drupal_static_reset('system_rebuild_module_data');
+    \Drupal::service('module_listing')->reset();
 
     $result = $this->moduleInstaller()->install(array('color'));
     $this->assertTrue($result, 'ModuleHandler::install() returns the correct value.');