diff --git a/tests/Unit/Crypt/AES/TestCase.php b/tests/Unit/Crypt/AES/TestCase.php
index 8a222c4e..fa789bb0 100644
--- a/tests/Unit/Crypt/AES/TestCase.php
+++ b/tests/Unit/Crypt/AES/TestCase.php
@@ -9,12 +9,12 @@ use phpseclib\Crypt\AES;
 use phpseclib\Crypt\Base;
 use phpseclib\Crypt\Rijndael;
 
-require_once 'Crypt/AES.php';
-
 abstract class Unit_Crypt_AES_TestCase extends PhpseclibTestCase
 {
     static public function setUpBeforeClass()
     {
+        include_once 'Crypt/AES.php';
+
         parent::setUpBeforeClass();
 
         self::reRequireFile('Crypt/Rijndael.php');
diff --git a/tests/Unit/Math/BigInteger/TestCase.php b/tests/Unit/Math/BigInteger/TestCase.php
index f84c852f..fae3eb0c 100644
--- a/tests/Unit/Math/BigInteger/TestCase.php
+++ b/tests/Unit/Math/BigInteger/TestCase.php
@@ -5,12 +5,12 @@
  * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
  */
 
-require_once 'Math/BigInteger.php';
-
 abstract class Unit_Math_BigInteger_TestCase extends PhpseclibTestCase
 {
     static public function setUpBeforeClass()
     {
+        include_once 'Math/BigInteger.php';
+
         parent::setUpBeforeClass();
 
         self::reRequireFile('Math/BigInteger.php');