diff --git a/phpunit.xml b/phpunit.xml
index 3aee4230..a940f772 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -2,7 +2,11 @@
 <phpunit colors="true">
     <testsuites>
         <testsuite name="Application Test Suite">
-            <directory>./tests</directory>
+            <directory>./unit_tests/php</directory>
         </testsuite>
     </testsuites>
+    <php>
+        <env name="DIR_BASE" value="webui/" />
+        <env name="TEST_FILES_DIR" value="test_files/" />
+    </php>
 </phpunit>
diff --git a/tests/EmailTest.php b/unit_tests/php/EmailTest.php
similarity index 83%
rename from tests/EmailTest.php
rename to unit_tests/php/EmailTest.php
index c872bc1a..7943b9b5 100644
--- a/tests/EmailTest.php
+++ b/unit_tests/php/EmailTest.php
@@ -2,8 +2,10 @@
 
 use PHPUnit\Framework\TestCase;
 
-include_once("webui/system/model.php");
-include_once("webui/model/search/search.php");
+define('DIR_BASE', $_ENV['DIR_BASE']);
+
+include_once(DIR_BASE . "system/model.php");
+include_once(DIR_BASE . "model/search/search.php");
 
 
 final class SearchSearchTest extends TestCase {
diff --git a/tests/FormatTest.php b/unit_tests/php/FormatTest.php
similarity index 100%
rename from tests/FormatTest.php
rename to unit_tests/php/FormatTest.php
diff --git a/tests/ParseMessageTest.php b/unit_tests/php/ParseMessageTest.php
similarity index 90%
rename from tests/ParseMessageTest.php
rename to unit_tests/php/ParseMessageTest.php
index 3d16e275..a1e10516 100644
--- a/tests/ParseMessageTest.php
+++ b/unit_tests/php/ParseMessageTest.php
@@ -2,7 +2,10 @@
 
 use PHPUnit\Framework\TestCase;
 
-require_once dirname(dirname(__FILE__)) . '/webui/system/helper/mime.php';
+define('DIR_BASE', $_ENV['DIR_BASE']);
+define('TEST_FILES_DIR', $_ENV['TEST_FILES_DIR']);
+
+require_once DIR_BASE . 'system/helper/mime.php';
 
 
 final class MailParserTest extends TestCase {
@@ -26,7 +29,7 @@ final class MailParserTest extends TestCase {
     * @dataProvider providerTestParseMessage
     */
    public function test_parse_message($input, $expected_part_count, $expected_body) {
-      $message = file_get_contents(dirname(dirname(__FILE__)) . "/test_files/" . $input);
+      $message = file_get_contents(TEST_FILES_DIR . $input);
       Piler_Mime_Decode::ParseMessage($message, $parts);
 
       $this->assertEquals(count($parts), $expected_part_count);
diff --git a/tests/SplitMessageTest.php b/unit_tests/php/SplitMessageTest.php
similarity index 98%
rename from tests/SplitMessageTest.php
rename to unit_tests/php/SplitMessageTest.php
index dc9d3dc7..e622662f 100644
--- a/tests/SplitMessageTest.php
+++ b/unit_tests/php/SplitMessageTest.php
@@ -7,7 +7,9 @@ define(THIS_IS_A_TEST, 'This is a test');
 
 use PHPUnit\Framework\TestCase;
 
-require_once dirname(dirname(__FILE__)) . '/webui/system/helper/mime.php';
+define('DIR_BASE', $_ENV['DIR_BASE']);
+
+require_once DIR_BASE . 'system/helper/mime.php';
 
 
 final class SplitMessageTest extends TestCase {