diff --git a/core/lib/Drupal/Core/Utility/LinkGenerator.php b/core/lib/Drupal/Core/Utility/LinkGenerator.php
index 70af473..a6b35b4 100644
--- a/core/lib/Drupal/Core/Utility/LinkGenerator.php
+++ b/core/lib/Drupal/Core/Utility/LinkGenerator.php
@@ -151,15 +151,15 @@ public function generate($text, Url $url) {
     // them. Include a placeholder for the href.
     $attributes = array('href' => '') + $variables['options']['attributes'];
     unset($variables['options']['attributes']);
-    $url->setOptions($variables['options']);
+    $variables['url']->setOptions($variables['options']);
 
     // External URLs can not have cacheable metadata.
-    if ($url->isExternal()) {
+    if ($variables['url']->isExternal()) {
       $generated_link = new GeneratedLink();
-      $attributes['href'] = $url->toString(FALSE);
+      $attributes['href'] = $variables['url']->toString(FALSE);
     }
     else {
-      $generated_url = $url->toString(TRUE);
+      $generated_url = $variables['url']->toString(TRUE);
       $generated_link = GeneratedLink::createFromObject($generated_url);
       // The result of the URL generator is a plain-text URL to use as the href
       // attribute, and it is escaped by \Drupal\Core\Template\Attribute.
diff --git a/core/modules/system/src/Tests/Utility/LinkGenerationTest.php b/core/modules/system/src/Tests/Utility/LinkGenerationTest.php
index 62c4d23..52dd584 100644
--- a/core/modules/system/src/Tests/Utility/LinkGenerationTest.php
+++ b/core/modules/system/src/Tests/Utility/LinkGenerationTest.php
@@ -65,6 +65,14 @@ function testHookLinkAlter() {
     // Ensure the content of the link is escaped.
     $this->assertEscaped('<em>link with markup</em>');
     $this->assertRaw('<strong>Test!</strong>');
+
+    // Test altering the url alteration.
+    \Drupal::state()->set('link_generation_test_link_alter_url', TRUE);
+    $link = $renderer->executeInRenderContext(new RenderContext(), function () use ($url) {
+      return \Drupal::l(['#markup' => '<em>link with markup</em>'], $url);
+    });
+    $this->setRawContent($link);
+    $this->assertLinkByHref('http://other-example.com');
   }
 
 }
diff --git a/core/modules/system/tests/modules/link_generation_test/link_generation_test.module b/core/modules/system/tests/modules/link_generation_test/link_generation_test.module
index 622a403..8210d4a 100644
--- a/core/modules/system/tests/modules/link_generation_test/link_generation_test.module
+++ b/core/modules/system/tests/modules/link_generation_test/link_generation_test.module
@@ -18,4 +18,8 @@ function link_generation_test_link_alter(&$variables) {
       $variables['text'] .= ' <strong>Test!</strong>';
     }
   }
+  if (\Drupal::state()->get('link_generation_test_link_alter_url', FALSE)) {
+    $new_url = \Drupal\Core\Url::fromUri('http://other-example.com');
+    $variables['url'] = $new_url;
+  }
 }