diff --git a/core/modules/picture/lib/Drupal/picture/Tests/PictureThemeFunctionsTest.php b/core/modules/picture/lib/Drupal/picture/Tests/PictureThemeFunctionsTest.php
index f923e6c..1578153 100644
--- a/core/modules/picture/lib/Drupal/picture/Tests/PictureThemeFunctionsTest.php
+++ b/core/modules/picture/lib/Drupal/picture/Tests/PictureThemeFunctionsTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\picture\Tests;
 
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\simpletest\WebTestBase;
 
 /**
@@ -19,7 +20,14 @@ class PictureThemeFunctionsTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = array('picture');
+  public static $modules = array('picture', 'entity_test');
+
+  /**
+   * Created file entity.
+   *
+   * @var \Drupal\file\Entity\File
+   */
+  protected $image;
 
   public static function getInfo() {
     return array(
@@ -29,6 +37,28 @@ public static function getInfo() {
     );
   }
 
+  public function setUp() {
+    parent::setUp();
+
+    entity_create('field_entity', array(
+      'name' => 'image_test',
+      'entity_type' => 'entity_test',
+      'type' => 'image',
+      'cardinality' => FieldDefinitionInterface::CARDINALITY_UNLIMITED,
+    ))->save();
+    entity_create('field_instance', array(
+      'entity_type' => 'entity_test',
+      'field_name' => 'image_test',
+      'bundle' => 'entity_test',
+    ))->save();
+    file_unmanaged_copy(DRUPAL_ROOT . '/core/misc/druplicon.png', 'public://example.jpg');
+    $this->image = entity_create('file', array(
+      'uri' => 'public://example.jpg',
+    ));
+    $this->image->save();
+    $this->imageFactory = $this->container->get('image.factory');
+  }
+
   /**
    * Tests usage of the theme_picture() function.
    */
@@ -78,28 +108,35 @@ function testPictureFormatterThemeFunction() {
     $style->save();
     $url = $style->buildUrl($original_uri);
 
-    // Test using theme_picture_formatter() without breakpoints and with a NULL value for the alt option.
+    // Create a test entity with the image field set.
+    $entity = entity_create('entity_test', array());
+    $entity->image_test->target_id = $this->image->id();
+    $entity->image_test->alt = NULL;
+    $entity->image_test->uri = $original_uri;
+    $image = $this->imageFactory->get('public://example.jpg');
+    $entity->save();
+
     $path = $this->randomName();
     $element = array(
       '#theme' => 'picture_formatter',
-      '#item' => array(
-        'uri' => $original_uri,
-        'alt' => NULL,
-      ),
+      '#item' => $entity->image_test,
       '#image_style' => 'test',
       '#path' => array(
         'path' => $path,
       ),
     );
+
+    // Test using theme_picture_formatter() without breakpoints and with a NULL
+    // value for the alt option.
     $rendered_element = render($element);
-    $expected_result = '<a href="' . base_path() . $path . '"><img class="image-style-test" src="' . $url . '" /></a>';
+    $expected_result = '<a href="' . base_path() . $path . '"><img class="image-style-test" src="' . $url . '" width="' . $image->getWidth() . '" height="' . $image->getHeight() . '" /></a>';
     $this->assertEqual($expected_result, $rendered_element, 'theme_picture_formatter() correctly renders without breakpoints and with a NULL value for the alt option.');
 
     // Test using theme_picture_formatter() without an image title, alt text, or
     // link options.
-    unset($element['#item']['alt']);
+    $element['#item']->alt = '';
     $rendered_element = render($element);
-    $expected_result = '<a href="' . base_path() . $path . '"><img class="image-style-test" src="' . $url . '" alt="" /></a>';
+    $expected_result = '<a href="' . base_path() . $path . '"><img class="image-style-test" src="' . $url . '" width="' . $image->getWidth() . '" height="' . $image->getHeight() . '" alt="" /></a>';
     $this->assertEqual($expected_result, $rendered_element, 'theme_picture_formatter() correctly renders without title, alt, or path options.');
 
     // Link the image to a fragment on the page, and not a full URL.
@@ -110,7 +147,7 @@ function testPictureFormatterThemeFunction() {
       'fragment' => $fragment,
     );
     $rendered_element = render($element);
-    $expected_result = '<a href="#' . $fragment . '"><img class="image-style-test" src="' . $url . '" alt="" /></a>';
+    $expected_result = '<a href="#' . $fragment . '"><img class="image-style-test" src="' . $url . '" width="' . $image->getWidth() . '" height="' . $image->getHeight() . '" alt="" /></a>';
     $this->assertEqual($expected_result, $rendered_element, 'theme_picture_formatter() correctly renders a link fragment.');
   }
 }
diff --git a/core/modules/picture/picture.module b/core/modules/picture/picture.module
index 9232189..73aa053 100644
--- a/core/modules/picture/picture.module
+++ b/core/modules/picture/picture.module
@@ -290,7 +290,7 @@ function theme_picture($variables) {
   if (!empty($sources)) {
     $attributes = array();
     foreach (array('alt', 'title') as $key) {
-      if (isset($variables[$key])) {
+      if (isset($variables[$key]) || array_key_exists($key, $variables)) {
         $attributes[$key] = $variables[$key];
       }
     }