diff --git a/system/core/compat/hash.php b/system/core/compat/hash.php
index 6854e4c..d567d0f 100644
--- a/system/core/compat/hash.php
+++ b/system/core/compat/hash.php
@@ -119,7 +119,7 @@
 	 */
 	function hash_pbkdf2($algo, $password, $salt, $iterations, $length = 0, $raw_output = FALSE)
 	{
-		if ( ! in_array($algo, hash_algos(), TRUE))
+		if ( ! in_array(strtolower($algo), hash_algos(), TRUE))
 		{
 			trigger_error('hash_pbkdf2(): Unknown hashing algorithm: '.$algo, E_USER_WARNING);
 			return FALSE;