diff --git a/components/script/dom/webidls/HTMLImageElement.webidl b/components/script/dom/webidls/HTMLImageElement.webidl
index 34cd6f5d645..c063301cb39 100644
--- a/components/script/dom/webidls/HTMLImageElement.webidl
+++ b/components/script/dom/webidls/HTMLImageElement.webidl
@@ -32,3 +32,9 @@ partial interface HTMLImageElement {
 
   [TreatNullAs=EmptyString] attribute DOMString border;
 };
+
+// https://drafts.csswg.org/cssom-view/#extensions-to-the-htmlimageelement-interface
+partial interface HTMLImageElement {
+  // readonly attribute long x;
+  // readonly attribute long y;
+};