diff --git a/testing/web-platform/tests/html/semantics/interactive-elements/the-details-element/toggleEvent.html b/testing/web-platform/tests/html/semantics/interactive-elements/the-details-element/toggleEvent.html
index a54ad1f8a8e7..c918f8eb6212 100644
--- a/testing/web-platform/tests/html/semantics/interactive-elements/the-details-element/toggleEvent.html
+++ b/testing/web-platform/tests/html/semantics/interactive-elements/the-details-element/toggleEvent.html
@@ -175,4 +175,9 @@
     t10.done();
   }, 0);
 
+  async_test(function(t) {
+    new DOMParser().parseFromString("<details open>", "text/html").querySelector("details").ontoggle = t.step_func_done(function(e) {
+      assert_true(e.target.open);
+    });
+  }, "Setting open from the parser fires a toggle event");
 </script>