diff --git a/lib/index.js b/lib/index.js
index 24c87e6b..44ec5287 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -44,7 +44,8 @@ rpc.on('session add', data => {
   store_.dispatch(sessionActions.addSession(data));
 });
 
-let req, objects = {}
+let req;
+let objects = {};
 rpc.on('session data', ({uid, data}) => {
   if (objects[uid] === undefined) {
     objects[uid] = data;
@@ -52,13 +53,15 @@ rpc.on('session data', ({uid, data}) => {
     objects[uid] += data;
   }
   if (!req) {
-    req = requestAnimationFrame(function () {
-      for (var i in objects) {
-        store_.dispatch(sessionActions.addSessionData(i, objects[i]));
+    req = requestAnimationFrame(() => {
+      for (const i in objects) {
+        if ({}.hasOwnProperty.call(objects, i)) {
+          store_.dispatch(sessionActions.addSessionData(i, objects[i]));
+        }
       }
       objects = {};
       req = null;
-    })
+    });
   }
 });