diff --git a/core/lib/Drupal/Core/Template/TwigExtension.php b/core/lib/Drupal/Core/Template/TwigExtension.php
index 95ccb60..3fcbe2c 100644
--- a/core/lib/Drupal/Core/Template/TwigExtension.php
+++ b/core/lib/Drupal/Core/Template/TwigExtension.php
@@ -605,7 +605,8 @@ public function safeJoin(\Twig_Environment $env, $value, $glue = '') {
    * Creates an Attribute object.
    *
    * @param array $attributes
-   *   An associative array of key-value pairs to be converted to attributes.
+   *   (optional) An associative array of key-value pairs to be converted to
+   *   HTML attributes.
    *
    * @return \Drupal\Core\Template\Attribute
    *   An attributes object that has the given attributes.
diff --git a/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
index 6e5b674..10438c1 100644
--- a/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
+++ b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
@@ -319,6 +319,11 @@ public function testCreateAttribute() {
     $result = $twig->render("{% for iteration in iterations %}<div{{ create_attribute(iteration) }}></div>{% endfor %}", ['iterations' => $iterations]);
     $expected = '<div class="kittens" data-toggle="modal" data-lang="es"></div><div id="puppies" data-value="foo" data-lang="en"></div><div></div>';
     $this->assertEquals($expected, $result);
+
+    // Test default creation of empty attribute object and using it's method.
+    $result = $twig->render("<div{{ create_attribute().addClass('meow') }}></div>");
+    $expected = '<div class="meow"></div>';
+    $this->assertEquals($expected, $result);
   }
 
 }