diff --git a/composer.json b/composer.json
index 722f1fa..32902ef 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,8 @@
     "zendframework/zend-feed": "2.3.*",
     "mikey179/vfsStream": "1.*",
     "stack/builder": "1.0.*",
-    "egulias/email-validator": "1.2.*"
+    "egulias/email-validator": "1.2.*",
+    "phpunit/phpunit-dom-assertions": "1.0.*@dev"
   },
   "autoload": {
     "psr-4": {
diff --git a/composer.lock b/composer.lock
index fe5dc0a..92f4d79 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at http://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "461047a83f0f5554064bfe97e2a673fb",
+    "hash": "727832d70cecdf01882aaf39bb183300",
     "packages": [
         {
             "name": "doctrine/annotations",
@@ -1088,6 +1088,63 @@
             "time": "2014-07-18 07:15:58"
         },
         {
+            "name": "phpunit/phpunit-dom-assertions",
+            "version": "dev-master",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/phpunit/phpunit-dom-assertions.git",
+                "reference": "4e43c66e35fb5e30a0eeb535c861455540c0d9fb"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpunit/phpunit-dom-assertions/zipball/4e43c66e35fb5e30a0eeb535c861455540c0d9fb",
+                "reference": "4e43c66e35fb5e30a0eeb535c861455540c0d9fb",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.3",
+                "phpunit/phpunit": "~4.0",
+                "symfony/css-selector": "~2.0",
+                "symfony/dom-crawler": "~2.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.0.x-dev"
+                }
+            },
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Jeff Welch",
+                    "email": "whatthejeff@gmail.com"
+                },
+                {
+                    "name": "Sebastian Bergmann",
+                    "email": "sebastian@phpunit.de"
+                }
+            ],
+            "description": "DOM assertions for PHPUnit",
+            "homepage": "http://github.com/phpunit/phpunit-dom-assertions",
+            "keywords": [
+                "Xpath",
+                "assertions",
+                "css",
+                "dom",
+                "phpunit",
+                "tests"
+            ],
+            "time": "2014-08-27 18:14:08"
+        },
+        {
             "name": "phpunit/phpunit-mock-objects",
             "version": "dev-master",
             "source": {
@@ -1860,6 +1917,59 @@
             "time": "2014-12-03 09:22:11"
         },
         {
+            "name": "symfony/dom-crawler",
+            "version": "v2.6.1",
+            "target-dir": "Symfony/Component/DomCrawler",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/DomCrawler.git",
+                "reference": "300d449f79d74ac62b06edd05214e8dd2e635840"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/DomCrawler/zipball/300d449f79d74ac62b06edd05214e8dd2e635840",
+                "reference": "300d449f79d74ac62b06edd05214e8dd2e635840",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.3"
+            },
+            "require-dev": {
+                "symfony/css-selector": "~2.0"
+            },
+            "suggest": {
+                "symfony/css-selector": ""
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "2.6-dev"
+                }
+            },
+            "autoload": {
+                "psr-0": {
+                    "Symfony\\Component\\DomCrawler\\": ""
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Symfony Community",
+                    "homepage": "http://symfony.com/contributors"
+                },
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                }
+            ],
+            "description": "Symfony DomCrawler Component",
+            "homepage": "http://symfony.com",
+            "time": "2014-12-02 20:19:20"
+        },
+        {
             "name": "symfony/event-dispatcher",
             "version": "v2.6.1",
             "target-dir": "Symfony/Component/EventDispatcher",
@@ -2594,7 +2704,8 @@
     "minimum-stability": "stable",
     "stability-flags": {
         "doctrine/common": 20,
-        "phpunit/phpunit-mock-objects": 20
+        "phpunit/phpunit-mock-objects": 20,
+        "phpunit/phpunit-dom-assertions": 20
     },
     "prefer-stable": false,
     "prefer-lowest": false,
diff --git a/core/tests/Drupal/Tests/UnitTestCase.php b/core/tests/Drupal/Tests/UnitTestCase.php
index 1a0ac77..b52f42a 100644
--- a/core/tests/Drupal/Tests/UnitTestCase.php
+++ b/core/tests/Drupal/Tests/UnitTestCase.php
@@ -16,7 +16,7 @@
  *
  * @ingroup testing
  */
-abstract class UnitTestCase extends \PHPUnit_Framework_TestCase {
+abstract class UnitTestCase extends \PHPUnit_Framework_DOMTestCase {
 
   /**
    * The random generator.