diff --git a/src/Formatters/Integer.php b/src/Formatters/Integer.php
index fbf045f..597697d 100644
--- a/src/Formatters/Integer.php
+++ b/src/Formatters/Integer.php
@@ -25,10 +25,20 @@ class Integer implements IFormatter
      */
     public static function format($value)
     {
+        $value = (string) $value;
+        $arguments = func_get_args();
+        $digit = 64;
+
+        if (isset($arguments[1]) && is_numeric($arguments[1])) {
+            $digit = intval($arguments[1]);
+        }
         $bn = Utils::toBn($value);
         $bnHex = $bn->toHex(true);
         $padded = mb_substr($bnHex, 0, 1);
-        
-        return implode('', array_fill(0, 64-mb_strlen($bnHex), $padded)) . $bnHex;
+
+        if ($padded !== 'f') {
+            $padded = '0';
+        }        
+        return implode('', array_fill(0, $digit-mb_strlen($bnHex), $padded)) . $bnHex;
     }
 }
\ No newline at end of file