diff --git a/tests/Unit/Crypt/TripleDESTest.php b/tests/Unit/Crypt/TripleDESTest.php
index 6afb832f..a1b07f86 100644
--- a/tests/Unit/Crypt/TripleDESTest.php
+++ b/tests/Unit/Crypt/TripleDESTest.php
@@ -173,7 +173,7 @@ class Unit_Crypt_TripleDESTest extends PhpseclibTestCase
         foreach ($this->engines as $engine => $engineName) {
             $des->setPreferredEngine($engine);
             if (!$des->isValidEngine($engine)) {
-	        self::markTestSkipped('Unable to initialize ' . $engineName . ' engine');
+                self::markTestSkipped('Unable to initialize ' . $engineName . ' engine');
             }
             $result = bin2hex($des->encrypt(str_repeat('a', 16)));
             $this->assertEquals($result, $expected, "Failed asserting inner chainin worked correctly in $engineName engine");