diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index 2c8c667b3799..e3dd81d755a1 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -615868,7 +615868,7 @@
    "support"
   ],
   "html/semantics/forms/form-submission-target/form-target-iframe.html": [
-   "2309ca67bb58f20f06a4c0b6ed162f2d0c80217f",
+   "f37bc33f6f93ca94940ffeb0066945eb9aa020ee",
    "testharness"
   ],
   "html/semantics/forms/historical.html": [
diff --git a/tests/wpt/web-platform-tests/html/semantics/forms/form-submission-target/form-target-iframe.html b/tests/wpt/web-platform-tests/html/semantics/forms/form-submission-target/form-target-iframe.html
index 2309ca67bb58..f37bc33f6f93 100644
--- a/tests/wpt/web-platform-tests/html/semantics/forms/form-submission-target/form-target-iframe.html
+++ b/tests/wpt/web-platform-tests/html/semantics/forms/form-submission-target/form-target-iframe.html
@@ -4,7 +4,7 @@
 <script src="/resources/testharnessreport.js"></script>
 <script>
 async_test(function(t) {
-  window.addEventListener("load", function() {
+  window.addEventListener("load", t.step_func(function() {
     var frame = document.createElement("iframe");
     frame.name = "frame";
     document.documentElement.appendChild(frame);
@@ -17,13 +17,13 @@
     form.appendChild(input);
     document.documentElement.appendChild(form);
     form.submit();
-    frame.addEventListener("load", function() {
-      if (frame.contentWindow.location.href != "about:blank") {
+    frame.addEventListener("load", t.step_func(function() {
+      if (frame.contentWindow.location.href.includes("form-target-iframe-helper.py")) {
         assert_equals(frame.contentWindow.document.body.textContent, "OK");
         t.done();
       }
-    });
-  });
+    }));
+  }));
 }, "Form targetted at iframe");
 </script>
 <body>
