diff --git a/check.php b/check.php
index a3f93ef..4c60d4e 100755
--- a/check.php
+++ b/check.php
@@ -258,7 +258,7 @@ function return_bytes($val) {
       $val = trim($val);
       if($val != '')
       {
-      $last = strtolower($val{strlen($val)-1});
+      $last = strtolower($val[strlen($val)-1]);
       switch($last) {
           // The 'G' modifier is available since PHP 5.1.0
           case 'g':