diff --git a/client/gesso.js b/client/gesso.js
index <HASH>..<HASH> 100644
--- a/client/gesso.js
+++ b/client/gesso.js
@@ -9,9 +9,6 @@ var logging = require('./logging');
 function Gesso(options) {
   options = options || {};
   this.scriptUrl = Gesso.getScriptUrl();
-  this.asset = function (assetPath) {
-    return url.resolve(this.scriptUrl, path.join('assets', assetPath));
-  };
   this.contextType = options.contextType || '2d';
   this.contextAttributes = options.contextAttributes;
   this.fps = options.fps || 60;
@@ -74,6 +71,9 @@ Gesso.prototype.run = function run(canvas) {
   controller.start();
   return controller;
 };
+Gesso.prototype.asset = function asset(assetPath) {
+  return url.resolve(this.scriptUrl, path.join('assets', assetPath));
+};
 
 
 module.exports = Gesso;
Move asset method from instance to protocol.