diff --git a/index.js b/index.js
index ca80a4a..7416955 100644
--- a/index.js
+++ b/index.js
@@ -1,4 +1,6 @@
-window.myDebug = require('debug')
+if (typeof window !== 'undefined') {
+  window.myDebug = require('debug')
+}
 var Peer = require('simple-peer')
 var Emitter = require('component-emitter')
 var parser = require('socket.io-p2p-parser')