Consistently use _ELEMENT constant.
diff --git a/lib/src/web_driver.dart b/lib/src/web_driver.dart
index 6b28e55..093be62 100644
--- a/lib/src/web_driver.dart
+++ b/lib/src/web_driver.dart
@@ -56,7 +56,7 @@
       var elements = await _post('elements', by);
       int i = 0;
       for (var element in elements) {
-        controller.add(new WebElement._(this, element['ELEMENT'], this, by, i));
+        controller.add(new WebElement._(this, element[_ELEMENT], this, by, i));
         i++;
       }
       await controller.close();
@@ -71,7 +71,7 @@
 //    int i = 0;
 //
 //    for (var element in elements) {
-//      yield new WebElement._(this, element['ELEMENT'], this, by, i);
+//      yield new WebElement._(this, element[_ELEMENT], this, by, i);
 //      i++;
 //    }
 //  }
@@ -83,7 +83,7 @@
    */
   Future<WebElement> findElement(By by) async {
     var element = await _post('element', by);
-    return new WebElement._(this, element['ELEMENT'], this, by);
+    return new WebElement._(this, element[_ELEMENT], this, by);
   }
 
   /// An artist's rendition of the current page's source.
@@ -136,7 +136,7 @@
   Future<WebElement> get activeElement async {
     var element = await _post('element/active');
     if (element != null) {
-      return new WebElement._(this, element['ELEMENT'], this, 'activeElement');
+      return new WebElement._(this, element[_ELEMENT], this, 'activeElement');
     }
     return null;
   }
@@ -204,7 +204,7 @@
   dynamic _recursiveElementify(result) {
     if (result is Map) {
       if (result.length == 1 && result.containsKey(_ELEMENT)) {
-        return new WebElement._(this, result['ELEMENT'], this, 'javascript');
+        return new WebElement._(this, result[_ELEMENT], this, 'javascript');
       } else {
         var newResult = {};
         result.forEach((key, value) {
diff --git a/lib/src/web_element.dart b/lib/src/web_element.dart
index 8046313..9721529 100644
--- a/lib/src/web_element.dart
+++ b/lib/src/web_element.dart
@@ -70,7 +70,7 @@
    */
   Future<WebElement> findElement(By by) async {
     var element = await _post('element', by);
-    return new WebElement._(driver, element['ELEMENT'], this, by);
+    return new WebElement._(driver, element[_ELEMENT], this, by);
   }
 
   /// Find multiple elements nested within this element.
@@ -82,7 +82,7 @@
       int i = 0;
       for (var element in elements) {
         controller
-            .add(new WebElement._(driver, element['ELEMENT'], this, by, i));
+            .add(new WebElement._(driver, element[_ELEMENT], this, by, i));
         i++;
       }
       await controller.close();
@@ -96,7 +96,7 @@
 //    var elements = await _post('elements', by);
 //    int i = 0;
 //    for (var element in elements) {
-//      yield new WebElement._(driver, element['ELEMENT'], this, by, i);
+//      yield new WebElement._(driver, element[_ELEMENT], this, by, i);
 //      i++;
 //    }
 //  }
@@ -122,7 +122,7 @@
    */
   Future<bool> equals(WebElement other) => _get('equals/${other.id}');
 
-  Map<String, String> toJson() => {'ELEMENT': id};
+  Map<String, String> toJson() => {_ELEMENT: id};
 
   @override
   int get hashCode => driver.hashCode * 3 + id.hashCode;