diff --git a/libraries/Gelato/Number/Number.php b/libraries/Gelato/Number/Number.php
index d5ef111..7170c3b 100644
--- a/libraries/Gelato/Number/Number.php
+++ b/libraries/Gelato/Number/Number.php
@@ -44,7 +44,7 @@ class Number
 
         $unit = array('b', 'kb', 'mb', 'gb', 'tb', 'pb');
 
-        return @round($size/pow(1024, ($i=floor(log($size, 1024)))), 2).' '.$unit[$i];
+        return @round($size/pow(1024, ($i=floor(log($size, 1024)))), 2).' '.$unit[($i < 0 ? 0 : $i)];
     }
 
     /**