diff --git a/unit_tests/php/ParseMessageTest.php b/unit_tests/php/ParseMessageTest.php
index a1e1051..fbf67cd 100644
--- a/unit_tests/php/ParseMessageTest.php
+++ b/unit_tests/php/ParseMessageTest.php
@@ -2,7 +2,6 @@
 
 use PHPUnit\Framework\TestCase;
 
-define('DIR_BASE', $_ENV['DIR_BASE']);
 define('TEST_FILES_DIR', $_ENV['TEST_FILES_DIR']);
 
 require_once DIR_BASE . 'system/helper/mime.php';
diff --git a/unit_tests/php/SplitMessageTest.php b/unit_tests/php/SplitMessageTest.php
index e622662..8947de6 100644
--- a/unit_tests/php/SplitMessageTest.php
+++ b/unit_tests/php/SplitMessageTest.php
@@ -1,14 +1,12 @@
 <?php
 
-define(CONTENT_TYPE, 'content-type');
-define(TEXT_PLAIN, 'text/plain');
-define(SUBJECT, 'subject');
-define(THIS_IS_A_TEST, 'This is a test');
+define('CONTENT_TYPE', 'content-type');
+define('TEXT_PLAIN', 'text/plain');
+define('SUBJECT', 'subject');
+define('THIS_IS_A_TEST', 'This is a test');
 
 use PHPUnit\Framework\TestCase;
 
-define('DIR_BASE', $_ENV['DIR_BASE']);
-
 require_once DIR_BASE . 'system/helper/mime.php';