1 files changed, 2 insertions, 1 deletions
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-fragment.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-fragment.html
index 6443ccecd1..69400c3d2f 100644
--- a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-fragment.html
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-fragment.html
@@ -17,7 +17,8 @@ async_test(t => {
     assert_equals(e.destination.key, "");
     assert_equals(e.destination.id, "");
     assert_equals(e.destination.index, -1);
-    assert_equals(e.sourceElement, document.getElementById("a"));
+    // NavigateEvent sourceElement is still in development, so test whether it is available.
+    if ("sourceElement" in e) assert_equals(e.sourceElement, document.getElementById("a"));
     e.preventDefault();
     t.step_timeout(t.step_func_done(() => assert_equals(location.hash, "")), 0);
   });