--- a/dom/clients/manager/ClientIPCUtils.h
+++ b/dom/clients/manager/ClientIPCUtils.h
@@ -3,19 +3,16 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef _mozilla_dom_ClientIPCUtils_h
 #define _mozilla_dom_ClientIPCUtils_h
 
 #include "ipc/IPCMessageUtils.h"
 
-// Fix X11 header brain damage that conflicts with FrameType::None
-#undef None
-
 #include "mozilla/dom/ClientBinding.h"
 #include "mozilla/dom/ClientsBinding.h"
 #include "mozilla/dom/DocumentBinding.h"
 #include "nsContentUtils.h"
 
 namespace IPC {
   template<>
   struct ParamTraits<mozilla::dom::ClientType> :

--- a/dom/fetch/FetchIPCTypes.h
+++ b/dom/fetch/FetchIPCTypes.h
@@ -4,19 +4,16 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_dom_fetch_IPCUtils_h
 #define mozilla_dom_fetch_IPCUtils_h
 
 #include "ipc/IPCMessageUtils.h"
 
-// Fix X11 header brain damage that conflicts with HeadersGuardEnum::None
-#undef None
-
 #include "mozilla/dom/HeadersBinding.h"
 #include "mozilla/dom/RequestBinding.h"
 #include "mozilla/dom/ResponseBinding.h"
 
 namespace IPC {
   template<>
   struct ParamTraits<mozilla::dom::HeadersGuardEnum> :
     public ContiguousEnumSerializer<mozilla::dom::HeadersGuardEnum,