diff --git a/rrd.js b/rrd.js
index 1e04027..2aa00e3 100644
--- a/rrd.js
+++ b/rrd.js
@@ -1,6 +1,6 @@
 (function() {
   var RRD, RRDRecord, exec, fs, spawn, sys;
-  sys = require('sys');
+  util = require('util');
   exec = require('child_process').exec;
   spawn = require('child_process').spawn;
   fs = require('fs');