diff --git a/lib/formatter.js b/lib/formatter.js
index e6e2726..04719e5 100644
--- a/lib/formatter.js
+++ b/lib/formatter.js
@@ -13,6 +13,7 @@
 var formatter = (function () {
 
     function repeat(s, count) {
+        count = count < 0 ? 0 : count;
         return new Array(count + 1).join(s);
     }
 
@@ -89,4 +90,4 @@ var formatter = (function () {
 
 if (typeof require !== 'undefined' && typeof exports !== 'undefined') {
   exports.formatter = formatter;
-}
\ No newline at end of file
+}