diff --git a/dart/async/lib/html.dart b/dart/async/lib/html.dart
index 6f5e17c0..3337d6d1 100644
--- a/dart/async/lib/html.dart
+++ b/dart/async/lib/html.dart
@@ -72,22 +72,25 @@ class _HtmlMouse implements PageLoaderMouse {
 
   @override
   Future down(MouseButton button,
-          {_ElementPageLoaderElement eventTarget, bool sync: true}) =>
+          {PageLoaderElement eventTarget, bool sync: true}) =>
       loader.executeSynced(
           () => dispatchEvent('mousedown', eventTarget, button), sync);
 
   @override
-  Future moveTo(_ElementPageLoaderElement element, int xOffset, int yOffset,
-          {_ElementPageLoaderElement eventTarget, bool sync: true}) =>
+  Future moveTo(PageLoaderElement element, int xOffset, int yOffset,
+          {PageLoaderElement eventTarget, bool sync: true}) =>
       loader.executeSynced(() {
-        clientX = (element.node.getBoundingClientRect().left + xOffset).ceil();
-        clientY = (element.node.getBoundingClientRect().top + yOffset).ceil();
+        if (element is _ElementPageLoaderElement) {
+          clientX =
+              (element.node.getBoundingClientRect().left + xOffset).ceil();
+          clientY = (element.node.getBoundingClientRect().top + yOffset).ceil();
+        }
         return dispatchEvent('mousemove', eventTarget);
       }, sync);
 
   @override
   Future up(MouseButton button,
-          {_ElementPageLoaderElement eventTarget, bool sync: true}) =>
+          {PageLoaderElement eventTarget, bool sync: true}) =>
       loader.executeSynced(() => dispatchEvent('mouseup', eventTarget), sync);
 
   int get pageX => window.pageXOffset + clientX;
diff --git a/dart/async/lib/src/core.dart b/dart/async/lib/src/core.dart
index 1b4ade26..34b964c9 100644
--- a/dart/async/lib/src/core.dart
+++ b/dart/async/lib/src/core.dart
@@ -377,7 +377,7 @@ class _ListFieldInfo extends _FieldInfo {
       : super._(fieldName);
 
   @override
-  Future<List> calculateFieldValue(PageLoaderElement context,
+  Future calculateFieldValue(PageLoaderElement context,
       BasePageLoader loader, bool displayCheck) async {
     if (!_displayCheck) {
       displayCheck = false;
@@ -405,10 +405,10 @@ class _LazyFieldInfo extends _FieldInfo {
         super._(impl._fieldName);
 
   @override
-  calculateFieldValue(
+  Future calculateFieldValue(
       PageLoaderElement context, BasePageLoader loader, bool displayCheck) {
-    return new _Lazy(
-        () => _impl.calculateFieldValue(context, loader, displayCheck));
+    return new Future.value(new _Lazy(
+        () => _impl.calculateFieldValue(context, loader, displayCheck)));
   }
 }
 
@@ -416,9 +416,8 @@ class _InjectedPageLoaderFieldInfo extends _FieldInfo {
   _InjectedPageLoaderFieldInfo(Symbol fieldName) : super._(fieldName);
 
   @override
-  calculateFieldValue(PageLoaderElement context, BasePageLoader loader,
-          bool displayCheck) =>
-      loader;
+  Future calculateFieldValue(PageLoaderElement context, BasePageLoader loader,
+          bool displayCheck) => new Future.value(loader);
 }
 
 Stream _getElements(PageLoaderElement context, Finder finder,
diff --git a/dart/async/lib/webdriver.dart b/dart/async/lib/webdriver.dart
index 6bde912d..b402d822 100644
--- a/dart/async/lib/webdriver.dart
+++ b/dart/async/lib/webdriver.dart
@@ -65,7 +65,7 @@ class _WebDriverMouse implements PageLoaderMouse {
 
   @override
   Future down(MouseButton button,
-          {_WebElementPageLoaderElement eventTarget, bool sync: true}) =>
+          {PageLoaderElement eventTarget, bool sync: true}) =>
       loader.executeSynced(() {
         if (eventTarget == null) {
           return driver.mouse.down(button);
@@ -74,10 +74,10 @@ class _WebDriverMouse implements PageLoaderMouse {
       }, sync);
 
   @override
-  Future moveTo(_WebElementPageLoaderElement element, int xOffset, int yOffset,
-          {_WebElementPageLoaderElement eventTarget, bool sync: true}) =>
+  Future moveTo(PageLoaderElement element, int xOffset, int yOffset,
+          {PageLoaderElement eventTarget, bool sync: true}) =>
       loader.executeSynced(() {
-        if (eventTarget == null) {
+        if (eventTarget == null && element is _WebElementPageLoaderElement) {
           return driver.mouse.moveTo(
               element: element.context, xOffset: xOffset, yOffset: yOffset);
         }
@@ -86,7 +86,7 @@ class _WebDriverMouse implements PageLoaderMouse {
 
   @override
   Future up(MouseButton button,
-          {_WebElementPageLoaderElement eventTarget, bool sync: true}) =>
+          {PageLoaderElement eventTarget, bool sync: true}) =>
       loader.executeSynced(() {
         if (eventTarget == null) {
           return driver.mouse.up(button);
@@ -94,12 +94,16 @@ class _WebDriverMouse implements PageLoaderMouse {
         return _fireEvent(eventTarget, 'mouseup', button);
       }, sync);
 
-  Future _fireEvent(_WebElementPageLoaderElement eventTarget, String type,
+  Future _fireEvent(PageLoaderElement eventTarget, String type,
           [MouseButton button]) =>
       driver.execute(
           "arguments[0].dispatchEvent(new MouseEvent(arguments[1], "
           "{'button' : arguments[2]}));",
-          [eventTarget.context, type, button?.value]);
+          [
+            (eventTarget as _WebElementPageLoaderElement).context,
+            type,
+            button?.value
+          ]);
 }
 
 abstract class WebDriverPageLoaderElement implements PageLoaderElement {