--- a/toolkit/content/l20n-perf-monitor.js
+++ b/toolkit/content/l20n-perf-monitor.js
@@ -38,16 +38,20 @@ setTimeout(() => {
   console.log(`navigationStart: ${performance.timing.navigationStart}`);
   timingEvents.forEach(eventName => {
     if (performance.timing[eventName]) {
       console.log(`${eventName}: ${performance.timing[eventName] - performance.timing.navigationStart}`);
     }
   });
 
   console.log('--- Performance.Marks ---');
-  let marks = performance.getEntriesByType('mark');
-  marks.forEach(mark => {
-    console.log(`${mark.startTime.toFixed(2)}: ${mark.name}`);
-  });
+  performance.getEntriesByType('mark').forEach(
+    mark => console.log(`${mark.startTime.toFixed(2)}: ${mark.name}`)
+  );
+
+  console.log('--- Performance.Measures ---');
+  performance.getEntriesByType('measure').forEach(
+    measure => console.log(`${measure.name}: ${measure.duration.toFixed(2)} ms`)
+  );
 }, 1000);
 
 window.addEventListener("MozAfterPaint", logFirstPaint, true);
 }