diff --git a/core/core.services.yml b/core/core.services.yml
index 6127c8f99bd..9f5ab7f2c5f 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -1280,7 +1280,7 @@ services:
     class: Drupal\Core\Asset\AssetDumper
   library.discovery:
     class: Drupal\Core\Asset\LibraryDiscovery
-    arguments: ['@library.discovery.collector', '@cache_tags.invalidator', '@module_handler', '@theme.manager']
+    arguments: ['@library.discovery.collector', '@cache_tags.invalidator']
   library.discovery.collector:
     class: Drupal\Core\Asset\LibraryDiscoveryCollector
     arguments: ['@cache.discovery', '@lock', '@library.discovery.parser', '@theme.manager']
diff --git a/core/lib/Drupal/Core/Asset/LibraryDiscovery.php b/core/lib/Drupal/Core/Asset/LibraryDiscovery.php
index 71926eea14e..31b8e4d55f3 100644
--- a/core/lib/Drupal/Core/Asset/LibraryDiscovery.php
+++ b/core/lib/Drupal/Core/Asset/LibraryDiscovery.php
@@ -31,20 +31,6 @@ class LibraryDiscovery implements LibraryDiscoveryInterface {
    */
   protected $cacheTagInvalidator;
 
-  /**
-   * The module handler.
-   *
-   * @var \Drupal\Core\Extension\ModuleHandlerInterface
-   */
-  protected $moduleHandler;
-
-  /**
-   * The theme manager.
-   *
-   * @var \Drupal\Core\Theme\ThemeManagerInterface
-   */
-  protected $themeManager;
-
   /**
    * The final library definitions, statically cached.
    *
@@ -67,11 +53,9 @@ class LibraryDiscovery implements LibraryDiscoveryInterface {
    * @param \Drupal\Core\Theme\ThemeManagerInterface $theme_manager
    *   The theme manager.
    */
-  public function __construct(CacheCollectorInterface $library_discovery_collector, CacheTagsInvalidatorInterface $cache_tag_invalidator, ModuleHandlerInterface $module_handler, ThemeManagerInterface $theme_manager) {
+  public function __construct(CacheCollectorInterface $library_discovery_collector, CacheTagsInvalidatorInterface $cache_tag_invalidator) {
     $this->collector = $library_discovery_collector;
     $this->cacheTagInvalidator = $cache_tag_invalidator;
-    $this->moduleHandler = $module_handler;
-    $this->themeManager = $theme_manager;
   }
 
   /**
@@ -85,8 +69,6 @@ class LibraryDiscovery implements LibraryDiscoveryInterface {
         // Allow modules and themes to dynamically attach request and context
         // specific data for this library; e.g., localization.
         $library_name = "$extension/$name";
-        $this->moduleHandler->alter('library', $definition, $library_name);
-        $this->themeManager->alter('library', $definition, $library_name);
         $this->libraryDefinitions[$extension][$name] = $definition;
       }
     }
diff --git a/core/tests/Drupal/Tests/Core/Asset/LibraryDiscoveryTest.php b/core/tests/Drupal/Tests/Core/Asset/LibraryDiscoveryTest.php
index 3492439d198..dafbdd4eb44 100644
--- a/core/tests/Drupal/Tests/Core/Asset/LibraryDiscoveryTest.php
+++ b/core/tests/Drupal/Tests/Core/Asset/LibraryDiscoveryTest.php
@@ -30,20 +30,6 @@ class LibraryDiscoveryTest extends UnitTestCase {
    */
   protected $libraryDiscoveryCollector;
 
-  /**
-   * The mocked module handler.
-   *
-   * @var \Drupal\Core\Extension\ModuleHandlerInterface|\PHPUnit_Framework_MockObject_MockObject
-   */
-  protected $moduleHandler;
-
-  /**
-   * The mocked theme manager.
-   *
-   * @var \Drupal\Core\Theme\ThemeManagerInterface|\PHPUnit_Framework_MockObject_MockObject
-   */
-  protected $themeManager;
-
   /**
    * The cache tags invalidator.
    *
@@ -81,9 +67,7 @@ class LibraryDiscoveryTest extends UnitTestCase {
     $this->libraryDiscoveryCollector = $this->getMockBuilder('Drupal\Core\Asset\LibraryDiscoveryCollector')
       ->disableOriginalConstructor()
       ->getMock();
-    $this->moduleHandler = $this->getMock('Drupal\Core\Extension\ModuleHandlerInterface');
-    $this->themeManager = $this->getMock('Drupal\Core\Theme\ThemeManagerInterface');
-    $this->libraryDiscovery = new LibraryDiscovery($this->libraryDiscoveryCollector, $this->cacheTagsInvalidator, $this->moduleHandler, $this->themeManager);
+    $this->libraryDiscovery = new LibraryDiscovery($this->libraryDiscoveryCollector, $this->cacheTagsInvalidator);
   }
 
   /**
@@ -94,20 +78,6 @@ class LibraryDiscoveryTest extends UnitTestCase {
       ->method('get')
       ->with('test')
       ->willReturn($this->libraryData);
-    $this->moduleHandler->expects($this->exactly(2))
-      ->method('alter')
-      ->with(
-        'library',
-        $this->logicalOr($this->libraryData['test_1'], $this->libraryData['test_2']),
-        $this->logicalOr('test/test_1', 'test/test_2')
-      );
-    $this->themeManager->expects($this->exactly(2))
-      ->method('alter')
-      ->with(
-        'library',
-        $this->logicalOr($this->libraryData['test_1'], $this->libraryData['test_2']),
-        $this->logicalOr('test/test_1', 'test/test_2')
-      );
 
     $this->libraryDiscovery->getLibrariesbyExtension('test');
     // Verify that subsequent calls don't trigger hook_library_info_alter()