diff --git a/samples/video-decode-display/worker.js b/samples/video-decode-display/worker.js
index c3600b9c..110f8177 100644
--- a/samples/video-decode-display/worker.js
+++ b/samples/video-decode-display/worker.js
@@ -58,6 +58,7 @@ function start({dataUri, rendererName, canvas}) {
       break;
   }
 
+  let lastTimestamp = -Infinity;
   // Set up a VideoDecoer.
   const decoder = new VideoDecoder({
     output(frame) {
@@ -70,6 +71,14 @@ function start({dataUri, rendererName, canvas}) {
         setStatus("render", `${fps.toFixed(0)} fps`);
       }
 
+
+      if (frame.timestamp < lastTimestamp) {
+        console.error(`Decoded frame ${frame.timestamp} µs out of order, last frame was ${lastTimestamp} µs`);
+      } else {
+        console.log(`Decoded frame ${frame.timestamp} µs`);
+      }
+      lastTimestamp = frame.timestamp;
+
       // Schedule the frame to be rendered.
       renderFrame(frame);
     },