diff --git a/lib/index.js b/lib/index.js
index b34c85a3..995c913d 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -4,6 +4,8 @@
 
 var keys = require('./keys')
 
+exports.protocol = '0.2.0';
+
 /**
  * Packet types.
  */