diff --git a/js/index.js b/js/index.js
index ebe0540a..cbc79f5e 100644
--- a/js/index.js
+++ b/js/index.js
@@ -173,7 +173,7 @@ Raven.context(async () => {
     return;
   }
   const __extraWindows = [];
-  let __initialWindowLayout = {};
+  let __initialWindowLayout = null;
 
   if (isButterchurnSupported()) {
     const startWithMilkdropHidden =