diff --git a/dom/webidl/ShadowRoot.webidl b/dom/webidl/ShadowRoot.webidl
index a6c6de2543..8dd069244c 100644
--- a/dom/webidl/ShadowRoot.webidl
+++ b/dom/webidl/ShadowRoot.webidl
@@ -17,7 +17,7 @@ interface ShadowRoot : DocumentFragment
   HTMLCollection getElementsByTagName(DOMString localName);
   HTMLCollection getElementsByTagNameNS(DOMString? namespace, DOMString localName);
   HTMLCollection getElementsByClassName(DOMString classNames);
-  [SetterThrows,TreatNullAs=EmptyString]
+  [CEReactions, SetterThrows, TreatNullAs=EmptyString]
   attribute DOMString innerHTML;
   readonly attribute Element host;
   readonly attribute ShadowRoot? olderShadowRoot;