--- a/dom/webidl/Window.webidl
+++ b/dom/webidl/Window.webidl
@@ -8,17 +8,16 @@
  * https://dvcs.w3.org/hg/editing/raw-file/tip/editing.html
  * https://dvcs.w3.org/hg/IndexedDB/raw-file/tip/Overview.html
  * http://dev.w3.org/csswg/cssom/
  * http://dev.w3.org/csswg/cssom-view/
  * https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/RequestAnimationFrame/Overview.html
  * https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html
  * https://dvcs.w3.org/hg/webcrypto-api/raw-file/tip/spec/Overview.html
  * http://dvcs.w3.org/hg/speech-api/raw-file/tip/speechapi.html
- * https://w3c.github.io/webappsec-secure-contexts/#monkey-patching-global-object
  */
 
 interface ApplicationCache;
 interface IID;
 interface nsIBrowserDOMWindow;
 interface nsIMessageBroadcaster;
 interface nsIDOMCrypto;
 typedef any Transferable;
@@ -414,21 +413,16 @@ partial interface Window {
 #endif
 
 // ConsoleAPI
 partial interface Window {
   [Replaceable, GetterThrows]
   readonly attribute Console console;
 };
 
-// https://w3c.github.io/webappsec-secure-contexts/#monkey-patching-global-object
-partial interface Window {
-  readonly attribute boolean isSecureContext;
-};
-
 #ifdef HAVE_SIDEBAR
 // Mozilla extension
 partial interface Window {
   [Replaceable, Throws, UseCounter]
   readonly attribute (External or WindowProxy) sidebar;
 };
 #endif