diff --git a/composer.json b/composer.json
index fd97b87..4f5ded2 100644
--- a/composer.json
+++ b/composer.json
@@ -47,6 +47,6 @@
         "pear/pear-core-minimal": "^1.10.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4"
+        "yoast/phpunit-polyfills": "^2.0"
     }
 }
diff --git a/package.xml b/package.xml
index 970e7dd..ce236f9 100644
--- a/package.xml
+++ b/package.xml
@@ -60,7 +60,6 @@ There are two classes to use for templating. HTML_Template_IT is used for basic
    <file name="HTML/Template/IT.php" role="php" />
    <file name="HTML/Template/ITX.php" role="php" />
    <file name="HTML/Template/IT_Error.php" role="php" />
-   <file name="tests/AllTests.php" role="test" />
    <file name="tests/ITTest.php" role="test" />
    <file name="tests/ITXTest.php" role="test" />
    <file name="tests/templates/addblock.html" role="test" />
diff --git a/tests/AllTests.php b/tests/AllTests.php
deleted file mode 100644
index 0059556..0000000
--- a/tests/AllTests.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-if (!defined('PHPUnit_MAIN_METHOD')) {
-    define('PHPUnit_MAIN_METHOD', 'HTML_Template_IT_AllTests::main');
-}
-
-
-
-require_once 'ITTest.php';
-require_once 'ITXTest.php';
-
-
-class HTML_Template_IT_AllTests
-{
-    public static function main()
-    {
-
-        PHPUnit_TextUI_TestRunner::run(self::suite());
-    }
-
-    public static function suite()
-    {
-        $suite = new PHPUnit_Framework_TestSuite('HTML_Template_IT tests');
-
-        $suite->addTestSuite('ITTest');
-        $suite->addTestSuite('ITXTest');
-
-        return $suite;
-    }
-}
-
-if (PHPUnit_MAIN_METHOD == 'HTML_Template_IT_AllTests::main') {
-    HTML_Template_IT_AllTests::main();
-}
-?>
diff --git a/tests/ITTest.php b/tests/ITTest.php
index ac95752..8854317 100644
--- a/tests/ITTest.php
+++ b/tests/ITTest.php
@@ -1,7 +1,10 @@
 <?php
+
+use Yoast\PHPUnitPolyfills\TestCases\TestCase;
+
 require_once 'HTML/Template/IT.php';
 
-class ITTest extends PHPUnit_Framework_TestCase
+class ITTest extends Yoast\PHPUnitPolyfills\TestCases\TestCase
 {
    /**
     * An HTML_Template_IT object
@@ -9,12 +12,12 @@ class ITTest extends PHPUnit_Framework_TestCase
     */
     var $tpl;
 
-    function setUp()
+    protected function set_up()
     {
         $this->tpl = new HTML_Template_IT(dirname(__FILE__) . '/templates');
     }
 
-    function tearDown()
+    protected function tear_down()
     {
         unset($this->tpl);
     }
diff --git a/tests/ITXTest.php b/tests/ITXTest.php
index 87f19c2..f5a728c 100644
--- a/tests/ITXTest.php
+++ b/tests/ITXTest.php
@@ -23,7 +23,7 @@ static function _numberFormatCallback($float, $decimals)
 
 class ITXTest extends ITTest
 {
-    function setUp()
+    function set_up()
     {
         $this->tpl = new HTML_Template_ITX(dirname(__FILE__) . '/templates');
     }