diff --git a/src/index.js b/src/index.js
index 128f6e1..40a826d 100644
--- a/src/index.js
+++ b/src/index.js
@@ -26,7 +26,7 @@ module.exports = class WebSockets {
     log('dialing %s', url)
     const socket = connect(url, {
       binary: true,
-      onConnect: () => callback
+      onConnect: () => callback()
     })
 
     const conn = new Connection(socket)