diff --git a/doc/api/perf_hooks.md b/doc/api/perf_hooks.md
index 74f8c115b486d4..7c3144939244b6 100644
--- a/doc/api/perf_hooks.md
+++ b/doc/api/perf_hooks.md
@@ -22,18 +22,18 @@ const { PerformanceObserver, performance } = require('node:perf_hooks');
 
 const obs = new PerformanceObserver((items) => {
   console.log(items.getEntries()[0].duration);
-  performance.clearMarks();
 });
 obs.observe({ type: 'measure' });
 performance.measure('Start to Now');
 
 performance.mark('A');
-doSomeLongRunningProcess(() => {
+(async function doSomeLongRunningProcess() {
+  await new Promise(r => setTimeout(r, 5000));
   performance.measure('A to Now', 'A');
 
   performance.mark('B');
   performance.measure('A to B', 'A', 'B');
-});
+})();
 ```
 
 ## `perf_hooks.performance`