diff --git a/js/xpconnect/tests/chrome/test_wrappers.xul b/js/xpconnect/tests/chrome/test_wrappers.xul
index 6f59f2383ea1..69da0e0a4a14 100644
--- a/js/xpconnect/tests/chrome/test_wrappers.xul
+++ b/js/xpconnect/tests/chrome/test_wrappers.xul
@@ -75,7 +75,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=500931
 
    // Test QI on new dom bindings.
    try {
-     var QIed = win.QueryInterface(Ci.nsIClassInfo);
+     var QIed = win.document.documentElement.QueryInterface(Ci.nsIClassInfo);
      ok(false, "Should throw for new binding objects not having classinfo");
    } catch(e) {
      is(e.name, "NS_NOINTERFACE", "Threw while QI-ing on wrapper");
diff --git a/testing/mochitest/tests/Harness_sanity/test_SpecialPowersExtension.html b/testing/mochitest/tests/Harness_sanity/test_SpecialPowersExtension.html
index 51e343b44236..989db4e5e3a9 100644
--- a/testing/mochitest/tests/Harness_sanity/test_SpecialPowersExtension.html
+++ b/testing/mochitest/tests/Harness_sanity/test_SpecialPowersExtension.html
@@ -82,9 +82,15 @@ async function starttest(){
   
   // QueryInterface and getPrivilegedProps tests
   is(SpecialPowers.can_QI(SpecialPowers), false);
-  ok(SpecialPowers.can_QI(window));
-  ok(SpecialPowers.do_QueryInterface(window, "nsIDOMWindow"));
-  is(SpecialPowers.getPrivilegedProps(SpecialPowers.do_QueryInterface(window, "nsIDOMWindow"), "document.nodeName"), "#document");
+  let doc = SpecialPowers.wrap(document);
+  is(SpecialPowers.getPrivilegedProps(doc, "baseURIObject.fileName"), null,
+     "Should not have a fileName property yet");
+  let uri = SpecialPowers.getPrivilegedProps(doc, "baseURIObject");
+  ok(SpecialPowers.can_QI(uri));
+  ok(SpecialPowers.do_QueryInterface(uri, "nsIURL"));
+  is(SpecialPowers.getPrivilegedProps(doc, "baseURIObject.fileName"),
+     "test_SpecialPowersExtension.html",
+     "Should have a fileName property now");
   
   //try to run garbage collection
   SpecialPowers.gc();