diff --git a/lib/context.js b/lib/context.js
index 4429d1d..51e847c 100644
--- a/lib/context.js
+++ b/lib/context.js
@@ -193,7 +193,8 @@ module.exports = {
    */
 
   get querystring() {
-    return parse(this.url).query || '';
+    var c = this._qscache = this._qscache || {};
+    return c[this.url] || (c[this.url] = parse(this.url).query || '');
   },
 
   /**