diff --git a/lib/index.js b/lib/index.js
index 44ec5287..4948a5f6 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -44,6 +44,8 @@ rpc.on('session add', data => {
   store_.dispatch(sessionActions.addSession(data));
 });
 
+// we aggregate all the incoming pty events by raf
+// debouncing, to reduce allocation and iterations
 let req;
 let objects = {};
 rpc.on('session data', ({uid, data}) => {