diff --git a/tests/wpt/web-platform-tests/html/semantics/document-metadata/the-base-element/base_multiple.html b/tests/wpt/web-platform-tests/html/semantics/document-metadata/the-base-element/base_multiple.html
index f56fd443bf0b..d8b9d7a1f5df 100644
--- a/tests/wpt/web-platform-tests/html/semantics/document-metadata/the-base-element/base_multiple.html
+++ b/tests/wpt/web-platform-tests/html/semantics/document-metadata/the-base-element/base_multiple.html
@@ -5,33 +5,23 @@
 <link rel="help" href="https://html.spec.whatwg.org/multipage/#the-base-element">
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
-<body onload="on_load()">
+<body>
   <div id="log"></div>
   <iframe id="test1" src="example.html" style="width:0;height:0" frameborder="0"></iframe>
   <iframe id="test2" src="example.html" name="targetWin" style="width:0;height:0" frameborder="0"></iframe>
   <script>
-    var t = async_test("The attributes of the a element must be affected by the first base element"),
-        doc1,
-        fr2,
-        a1;
-
-    function on_load() {
-      setup(function (){
-        doc1 = document.getElementById("test1").contentDocument;
-        fr2 = document.getElementById("test2");
-        a1 = doc1.getElementById("a1");
-      });
-
-      fr2.addEventListener("load", function () {
-        t.step(function () {
+    async_test(function() {
+      window.onload = this.step_func(function() {
+        var fr2 = document.getElementById("test2");
+        fr2.addEventListener("load", this.step_func_done(function () {
           var doc2 = fr2.contentDocument;
           assert_not_equals(doc2.location.href.indexOf("example2.html"), -1, "The target attribute does not impact the a element.");
           assert_equals(doc2.getElementById("d1").innerHTML, "PASS", "The opend page should be the example2.html.");
-        });
-        t.done();
-      }, true);
+        }), true);
 
-      a1.click();
-    }
+        var doc1 = document.getElementById("test1").contentDocument;
+        doc1.getElementById("a1").click();
+      });
+    }, "The attributes of the a element must be affected by the first base element");
   </script>
 </body>
