1 files changed, 3 insertions, 1 deletions
diff --git a/testing/web-platform/tests/css/css-scoping/font-face-005.html b/testing/web-platform/tests/css/css-scoping/font-face-005.html
index fdf86fb56e..de102f253e 100644
--- a/testing/web-platform/tests/css/css-scoping/font-face-005.html
+++ b/testing/web-platform/tests/css/css-scoping/font-face-005.html
@@ -12,7 +12,7 @@
 </style>
 <div id="host"><span id="in-document">1234567890</span></div>
 <script>
-test(function() {
+promise_test(async () => {
   host.attachShadow({ mode: "open" }).innerHTML = `
     <style>
       @font-face {
@@ -27,6 +27,8 @@ test(function() {
     <span id="in-shadow">0123456789</span>
   `;
 
+  await document.fonts.ready;
+
   assert_not_equals(document.getElementById('in-document').offsetWidth, 160);
   assert_equals(host.shadowRoot.getElementById('in-shadow').offsetWidth, 160);
 }, "@font-face should not leak out of shadow tree.");