diff --git a/components/script/dom/webidls/ParentNode.webidl b/components/script/dom/webidls/ParentNode.webidl
index 6618f046bb4..ef36324bca8 100644
--- a/components/script/dom/webidls/ParentNode.webidl
+++ b/components/script/dom/webidls/ParentNode.webidl
@@ -9,7 +9,7 @@
 
 [NoInterfaceObject]
 interface ParentNode {
-  [Constant]
+  [SameObject]
   readonly attribute HTMLCollection children;
   [Pure]
   readonly attribute Element? firstElementChild;
@@ -28,7 +28,6 @@ interface ParentNode {
   //Elements queryAll(DOMString relativeSelectors);
   [Throws]
   Element? querySelector(DOMString selectors);
-  //[NewObject]
-  [Throws]
+  [NewObject, Throws]
   NodeList querySelectorAll(DOMString selectors);
 };