diff --git a/aio/scripts/test-pwa-score.js b/aio/scripts/test-pwa-score.js
index 505ebc96c5..dae5cc28b5 100644
--- a/aio/scripts/test-pwa-score.js
+++ b/aio/scripts/test-pwa-score.js
@@ -79,6 +79,9 @@ function launchChromeAndRunLighthouse(url, flags, config) {
 
   return launcher.run().
     then(() => lighthouse(url, flags, config)).
+    // Avoid race condition by adding a delay before killing Chrome.
+    // (See also https://github.com/paulirish/pwmetrics/issues/63#issuecomment-282721068.)
+    then(results => new Promise(resolve => setTimeout(() => resolve(results), 1000))).
     then(results => launcher.kill().then(() => results)).
     catch(err => launcher.kill().then(() => { throw err; }, () => { throw err; }));
 }