diff --git a/system/libraries/Trackback.php b/system/libraries/Trackback.php
index 3bea5f9..be1de6f 100644
--- a/system/libraries/Trackback.php
+++ b/system/libraries/Trackback.php
@@ -141,7 +141,7 @@
 
 			$this->data['charset'] = ( ! isset($_POST['charset'])) ? 'auto' : strtoupper(trim($_POST['charset']));
 
-			if ($val != 'url' && function_exists('mb_convert_encoding'))
+			if ($val != 'url' && MB_ENABLED === TRUE)
 			{
 				$_POST[$val] = mb_convert_encoding($_POST[$val], $this->charset, $this->data['charset']);
 			}