diff --git a/src/Key/Derivation/SaltedS2k.php b/src/Key/Derivation/SaltedS2k.php
index c3dbda4..16bfd38 100644
--- a/src/Key/Derivation/SaltedS2k.php
+++ b/src/Key/Derivation/SaltedS2k.php
@@ -24,18 +24,18 @@ class SaltedS2k
         'md4'        => MHASH_MD4,
         'md5'        => MHASH_MD5,
         'sha1'       => MHASH_SHA1,
-	'sha224'     => MHASH_SHA224,
-	'sha256'     => MHASH_SHA256,
-	'sha382'     => MHASH_SHA384,
-	'sha512'     => MHASH_SHA512,
-	'ripemd128'  => MHASH_RIPEMD128,
-	'ripemd256'  => MHASH_RIPEMD256,
-	'ripemd320'  => MHASH_RIPEMD320,
-	'haval128,3' => MHASH_HAVAL128,
-	'haval160,3' => MHASH_HAVAL160,
-	'haval192,3' => MHASH_HAVAL192,
-	'haval224,3' => MHASH_HAVAL224,
-	'haval256,3' => MHASH_HAVAL256,
+        'sha224'     => MHASH_SHA224,
+        'sha256'     => MHASH_SHA256,
+        'sha382'     => MHASH_SHA384,
+        'sha512'     => MHASH_SHA512,
+        'ripemd128'  => MHASH_RIPEMD128,
+        'ripemd256'  => MHASH_RIPEMD256,
+        'ripemd320'  => MHASH_RIPEMD320,
+        'haval128,3' => MHASH_HAVAL128,
+        'haval160,3' => MHASH_HAVAL160,
+        'haval192,3' => MHASH_HAVAL192,
+        'haval224,3' => MHASH_HAVAL224,
+        'haval256,3' => MHASH_HAVAL256,
         'tiger128,3' => MHASH_TIGER128,
         'riger160,3' => MHASH_TIGER160,
         'whirpool'   => MHASH_WHIRLPOOL,
diff --git a/test/Key/Derivation/SaltedS2kTest.php b/test/Key/Derivation/SaltedS2kTest.php
index 6706689..6298006 100644
--- a/test/Key/Derivation/SaltedS2kTest.php
+++ b/test/Key/Derivation/SaltedS2kTest.php
@@ -44,6 +44,10 @@ public function setUp()
 
     public function testCalc()
     {
+        if (!extension_loaded('mhash')) {
+            $this->markTestSkipped('The mhash extension is not available');
+            return;
+        }
         $password = SaltedS2k::calc('sha256', 'test', $this->salt, 32);
         $this->assertEquals(32, strlen($password));
         $this->assertEquals('qzQISUBUSP1iqYtwe/druhdOVqluc/Y2TetdSHSbaw8=', base64_encode($password));
@@ -51,6 +55,10 @@ public function testCalc()
 
     public function testCalcWithWrongHash()
     {
+        if (!extension_loaded('mhash')) {
+            $this->markTestSkipped('The mhash extension is not available');
+            return;
+        }
         $this->setExpectedException('Zend\Crypt\Key\Derivation\Exception\InvalidArgumentException',
                                     'The hash algorihtm wrong is not supported by Zend\Crypt\Key\Derivation\SaltedS2k');
         $password = SaltedS2k::calc('wrong', 'test', $this->salt, 32);
@@ -58,6 +66,10 @@ public function testCalcWithWrongHash()
 
     public function testCalcWithWrongSalt()
     {
+        if (!extension_loaded('mhash')) {
+            $this->markTestSkipped('The mhash extension is not available');
+            return;
+        }
         $this->setExpectedException('Zend\Crypt\Key\Derivation\Exception\InvalidArgumentException',
                                     'The salt size must be at least of 8 bytes');
         $password = SaltedS2k::calc('sha256', 'test', substr($this->salt,-1), 32);