diff --git a/core/tests/Drupal/Tests/Core/Asset/LibraryDependencyResolverTest.php b/core/tests/Drupal/Tests/Core/Asset/LibraryDependencyResolverTest.php
index e8af816..5ab278a 100644
--- a/core/tests/Drupal/Tests/Core/Asset/LibraryDependencyResolverTest.php
+++ b/core/tests/Drupal/Tests/Core/Asset/LibraryDependencyResolverTest.php
@@ -60,10 +60,10 @@ class LibraryDependencyResolverTest extends UnitTestCase {
   protected function setUp() {
     $this->libraryDiscovery = $this->getMockBuilder('Drupal\Core\Asset\LibraryDiscovery')
       ->disableOriginalConstructor()
-      ->setMethods(['getLibrariesByExtension'])
+      ->setMethods(['getLibraryDefinitions'])
       ->getMock();
     $this->libraryDiscovery->expects($this->any())
-      ->method('getLibrariesByExtension')
+      ->method('getLibraryDefinitions')
       ->with('test')
       ->will($this->returnValue($this->libraryData));
     $this->libraryDependencyResolver= new LibraryDependencyResolver($this->libraryDiscovery);