diff --git a/core/modules/picture/lib/Drupal/picture/Tests/PictureThemeFunctionsTest.php b/core/modules/picture/lib/Drupal/picture/Tests/PictureThemeFunctionsTest.php
new file mode 100644
index 0000000..1148cc0
--- /dev/null
+++ b/core/modules/picture/lib/Drupal/picture/Tests/PictureThemeFunctionsTest.php
@@ -0,0 +1,67 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\picture\Tests\PictureThemeFunctionsTest.
+ */
+
+namespace Drupal\picture\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests picture theme functions.
+ */
+class PictureThemeFunctionsTest extends WebTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('picture');
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Picture theme functions',
+      'description' => 'Tests the picture theme functions.',
+      'group' => 'Picture',
+    );
+  }
+
+  /**
+   * Tests usage of the theme_picture() function.
+   */
+  function testPictureThemeFunction() {
+    // Create an image.
+    $files = $this->drupalGetTestFiles('image');
+    $file = reset($files);
+    $original_uri = file_unmanaged_copy($file->uri, 'public://', FILE_EXISTS_RENAME);
+
+    // Create a style.
+    $style = entity_create('image_style', array('name' => 'test', 'label' => 'Test'));
+    $style->save();
+    $url = $style->buildUrl($original_uri);
+
+    // Test using theme_picture() with a NULL value for the alt option.
+    $path = $this->randomName();
+    $element = array(
+      '#theme' => 'picture',
+      '#uri' => $original_uri,
+      '#alt' => NULL,
+      '#style_name' => 'test',
+    );
+    $rendered_element = render($element);
+    $expected_result = '<img class="image-style-test" src="' . $url . '" />';
+    $this->assertTrue(strpos($rendered_element, $expected_result) !== FALSE, 'img element in theme_picture() correctly renders with a NULL value for the alt option.');
+    $this->assertTrue(strpos($rendered_element, '<picture>') !== FALSE, 'picture element in theme_picture() correctly renders with a NULL value for the alt option.');
+
+    // Test using theme_picture() without passing a value for the alt option.
+    unset($element['#alt']);
+    $rendered_element = render($element);
+    $expected_result = '<img class="image-style-test" src="' . $url . '" alt="" />';
+    $this->assertTrue(strpos($rendered_element, $expected_result) !== FALSE, 'img element in theme_picture() correctly renders the alt option.');
+    $this->assertTrue(strpos($rendered_element, '<picture alt="">') !== FALSE, 'picture element in theme_picture() correctly renders the alt option.');
+  }
+
+}