diff --git a/dom/webidl/HTMLInputElement.webidl b/dom/webidl/HTMLInputElement.webidl
index 13f9f88d9..888a4a2a4 100644
--- a/dom/webidl/HTMLInputElement.webidl
+++ b/dom/webidl/HTMLInputElement.webidl
@@ -88,7 +88,7 @@ interface HTMLInputElement : HTMLElement {
attribute DOMString defaultValue;
[Pure, TreatNullAs=EmptyString, SetterThrows]
attribute DOMString value;
- [Throws, Pref="dom.experimental_forms"]
+ [Throws, Pref="tenfourfox.dom.forms.date"]
attribute Date? valueAsDate;
[Pure, SetterThrows]
attribute unrestricted double valueAsNumber;