diff --git a/src/operations/index.js b/src/operations/index.js
index 26dd022..e3b4823 100644
--- a/src/operations/index.js
+++ b/src/operations/index.js
@@ -18,8 +18,7 @@
 /* jshint node: true */
 'use strict';
 
-var moment     = require('moment'),
-    Highcharts = require('highstock-release');
+var moment     = require('moment');
 
 var angular = require('angular');