diff --git a/examples/channels.js b/examples/channels.js
index 3a51cf1..4fe1f18 100644
--- a/examples/channels.js
+++ b/examples/channels.js
@@ -2,6 +2,7 @@
  * This file showcases how to set up SseChannel instances,
  * some common configuration parameters and how to broadcast data
  */
+'use strict';
 
 // Should be `require('sse-channel')` when outside of sse-channel repo
 var SseChannel = require('../');