--- a/testing/mochitest/baselinecoverage/browser_chrome/browser_baselinecoverage.js
+++ b/testing/mochitest/baselinecoverage/browser_chrome/browser_baselinecoverage.js
@@ -3,11 +3,20 @@
 /* eslint-disable mozilla/no-arbitrary-setTimeout */
 
 "use strict";
 
 const { setTimeout } = ChromeUtils.import("resource://gre/modules/Timer.jsm", {});
 
 add_task(async function() {
   requestLongerTimeout(2);
-  ok(true, "Collecting baseline coverage for javascript (.js) file types.");
-  await new Promise((c) => setTimeout(c, 30 * 1000));
+  let newWin = await BrowserTestUtils.openNewBrowserWindow();
+
+  await BrowserTestUtils.withNewTab({
+    gBrowser,
+    url: "about:blank"
+  }, async function(browser) {
+    ok(true, "Collecting baseline coverage for javascript (.js) file types.");
+    await new Promise((c) => setTimeout(c, 30 * 1000));
+  });
+
+  await BrowserTestUtils.closeWindow(newWin);
 });