Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 17080)
+++ wp-includes/taxonomy.php	(working copy)
@@ -1574,6 +1574,7 @@
 		unset($args['ignore_empty']);
 	}
 
+	$args['hierarchical'] = false;
 	$args['fields'] = 'count';
 
 	return get_terms($taxonomy, $args);