diff --git a/core/lib/Drupal/Core/Template/TwigExtension.php b/core/lib/Drupal/Core/Template/TwigExtension.php
index cf0fa5f..a499db5 100644
--- a/core/lib/Drupal/Core/Template/TwigExtension.php
+++ b/core/lib/Drupal/Core/Template/TwigExtension.php
@@ -223,7 +223,7 @@ public function getUrlFromPath($path, $options = array()) {
    * @param \Drupal\Core\Url|string $url
    *   The URL object or string used for the link.
    * @param array $attributes
-   *   An array of link attributes.
+   *   An optional array of link attributes.
    *
    * @return array
    *   A render array representing a link to the given URL.
diff --git a/core/modules/system/tests/modules/twig_theme_test/templates/twig_theme_test.link_generator.html.twig b/core/modules/system/tests/modules/twig_theme_test/templates/twig_theme_test.link_generator.html.twig
index 6a02d97..9300dfc 100644
--- a/core/modules/system/tests/modules/twig_theme_test/templates/twig_theme_test.link_generator.html.twig
+++ b/core/modules/system/tests/modules/twig_theme_test/templates/twig_theme_test.link_generator.html.twig
@@ -1,4 +1,4 @@
 <div>link via the linkgenerator: {{ link("register", test_url) }}</div>
-<div>link via the linkgenerator: {{ link("register", test_url, { 'foo' : 'bar' }) }}</div>
-<div>link via the linkgenerator: {{ link("register", test_url_attribute, { 'id' : 'kitten' }) }}</div>
-<div>link via the linkgenerator: {{ link("register", url('user.register'), { 'id' : 'kitten' }) }}</div>
+<div>link via the linkgenerator: {{ link("register", test_url, { 'foo': 'bar' }) }}</div>
+<div>link via the linkgenerator: {{ link("register", test_url_attribute, { 'id': 'kitten' }) }}</div>
+<div>link via the linkgenerator: {{ link("register", url('user.register'), { 'id': 'kitten' }) }}</div>