--- a/dom/base/DOMPrefs.h	2018-01-25 11:33:55.000000000 -0400
+++ b/dom/base/DOMPrefs.h.new	2018-01-26 20:03:01.990422629 -0400
@@ -4,6 +4,8 @@
  * 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/. */
 
+#include "jsfriendapi.h"
+
 #ifndef mozilla_dom_DOMPrefs_h
 #define mozilla_dom_DOMPrefs_h