diff --git a/composer.json b/composer.json
index 28145af..b7f8aea 100644
--- a/composer.json
+++ b/composer.json
@@ -15,6 +15,9 @@
     "require": {
         "php": ">=5.3.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "^4.8.35"
+    },
     "autoload": {
         "psr-0": {"Parsedown": ""}
     }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index b2d5e9d..dd9da22 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -5,4 +5,4 @@
 			<file>test/ParsedownTest.php</file>
 		</testsuite>
 	</testsuites>
-</phpunit>
\ No newline at end of file
+</phpunit>
diff --git a/test/CommonMarkTest.php b/test/CommonMarkTest.php
index 9b8d116..7111f0b 100644
--- a/test/CommonMarkTest.php
+++ b/test/CommonMarkTest.php
@@ -8,7 +8,10 @@
  * @link http://commonmark.org/ CommonMark
  * @link http://git.io/8WtRvQ JavaScript test runner
  */
-class CommonMarkTest extends PHPUnit_Framework_TestCase
+
+use PHPUnit\Framework\TestCase;
+
+class CommonMarkTest extends TestCase
 {
     const SPEC_URL = 'https://raw.githubusercontent.com/jgm/stmd/master/spec.txt';
 
diff --git a/test/ParsedownTest.php b/test/ParsedownTest.php
index 323dace..3b4c7d9 100644
--- a/test/ParsedownTest.php
+++ b/test/ParsedownTest.php
@@ -1,6 +1,8 @@
 <?php
 
-class ParsedownTest extends PHPUnit_Framework_TestCase
+use PHPUnit\Framework\TestCase;
+
+class ParsedownTest extends TestCase
 {
     final function __construct($name = null, array $data = array(), $dataName = '')
     {
diff --git a/test/bootstrap.php b/test/bootstrap.php
index 3c78135..c89724b 100644
--- a/test/bootstrap.php
+++ b/test/bootstrap.php
@@ -1,7 +1,3 @@
 <?php
 
 include 'Parsedown.php';
-
-if ( ! class_exists('\PHPUnit_Framework_TestCase')) {
-    class_alias('\PHPUnit\Framework\TestCase', '\PHPUnit_Framework_TestCase');
-}