diff --git a/test/assets/favicon.ico b/test/assets/favicon.ico
new file mode 100644
index 0000000000000..d4edd507993e8
Binary files /dev/null and b/test/assets/favicon.ico differ
diff --git a/test/assets/offscreenbuttons.html b/test/assets/offscreenbuttons.html
index d45e2a41298df..005d465cbd994 100644
--- a/test/assets/offscreenbuttons.html
+++ b/test/assets/offscreenbuttons.html
@@ -1,3 +1,4 @@
+<!DOCTYPE html>
 <style>
   button {
     position: absolute;
@@ -29,8 +30,9 @@
 <button id=btn9>9</button>
 <button id=btn10>10</button>
 <script>
-window.addEventListener('DOMContentLoaded', () => {
-  for (const button of Array.from(document.querySelectorAll('button')))
-    button.addEventListener('click', () => console.log('button #' + button.textContent + ' clicked'), false);
-}, false);
+  for (const button of document.querySelectorAll('button')) {
+    button.addEventListener('click', () => {
+      console.log(`button #${button.textContent} clicked`);
+    });
+  }
 </script>
diff --git a/test/click.spec.ts b/test/click.spec.ts
index 2cc4fb7a10dd1..fa6f0309c1f38 100644
--- a/test/click.spec.ts
+++ b/test/click.spec.ts
@@ -132,7 +132,7 @@ describe('Page.click', function () {
       })
     ).toBe(text);
   });
-  itFailsFirefox('should click offscreen buttons', async () => {
+  it('should click offscreen buttons', async () => {
     const { page, server } = getTestState();
 
     await page.goto(server.PREFIX + '/offscreenbuttons.html');
