diff --git a/lib/thread.js b/lib/thread.js
index d951a0e..70db2bd 100644
--- a/lib/thread.js
+++ b/lib/thread.js
@@ -79,7 +79,7 @@ async function executeThread(thread, index) {
   const commandArguments = createCommandArguments(thread);
 
   // staggered start (when executed in container with xvfb ends up having a race condition causing intermittent failures)
-  await sleep(index * 2000);
+  await sleep((index +1) * 2000);
 
   const timeMap = new Map();