1 files changed, 3 insertions, 1 deletions
diff --git a/testing/web-platform/tests/css/css-scoping/font-face-008.html b/testing/web-platform/tests/css/css-scoping/font-face-008.html
index a40b0247d1..52c7869f9f 100644
--- a/testing/web-platform/tests/css/css-scoping/font-face-008.html
+++ b/testing/web-platform/tests/css/css-scoping/font-face-008.html
@@ -8,7 +8,7 @@
 
 <div id="host"><span id="in-document">1234567890</span></div>
 <script>
-test(function() {
+promise_test(async () => {
   host.attachShadow({ mode: "open" }).innerHTML = `
     <style>
       @font-face {
@@ -23,6 +23,8 @@ test(function() {
     <span id="in-shadow">0123456789</span>
   `;
 
+  await document.fonts.ready;
+
   assert_equals(document.getElementById('in-document').offsetWidth, 160);
   assert_not_equals(host.shadowRoot.getElementById('in-shadow').offsetWidth, 160);
 }, "@font-face from shadow applies to a slotted element");