diff --git a/lib/url.js b/lib/url.js
index 0302fda1427..ac82d251179 100644
--- a/lib/url.js
+++ b/lib/url.js
@@ -318,6 +318,8 @@ Url.prototype.parse = function(url, parseQueryString, slashesDenoteHost) {
     // need to be.
     for (var i = 0, l = autoEscape.length; i < l; i++) {
       var ae = autoEscape[i];
+      if (rest.indexOf(ae) === -1)
+        continue;
       var esc = encodeURIComponent(ae);
       if (esc === ae) {
         esc = escape(ae);