diff -u b/includes/common.inc b/includes/common.inc
--- b/includes/common.inc
+++ b/includes/common.inc
@@ -1995,7 +1995,7 @@
     $key = explode('|', $key);
     if ($interval >= $value) {
       $output .= ($output ? ' ' : '') . format_plural(floor($interval / $value), $key[0], $key[1], array(), array('langcode' => $langcode));
-      $interval = (int) ($interval % $value);
+      $interval = (int) $interval % $value;
       $granularity--;
     }