--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -648,16 +648,20 @@
 @RESPATH@/browser/defaults/permissions
 @RESPATH@/browser/defaults/blocklists
 
 ; Warning: changing the path to channel-prefs.js can cause bugs (Bug 756325)
 ; Technically this is an app pref file, but we are keeping it in the original
 ; gre location for now.
 @RESPATH@/defaults/pref/channel-prefs.js
 
+; Remote control protocol prefs
+; defined in ../../testing/marionette/prefs/marionette.js
+@RESPATH@/defaults/pref/marionette.js
+
 ; Services (gre) prefs
 @RESPATH@/defaults/pref/services-sync.js
 
 ; [Layout Engine Resources]
 ; Style Sheets, Graphics and other Resources used by the layout engine.
 @RESPATH@/res/EditorOverride.css
 @RESPATH@/res/contenteditable.css
 @RESPATH@/res/designmode.css

--- a/testing/marionette/moz.build
+++ b/testing/marionette/moz.build
@@ -1,15 +1,15 @@
 # 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/.
 
 DIRS += ["components"]
 
-JS_PREFERENCE_FILES += ["prefs.js"]
+JAR_MANIFESTS += ["jar.mn"]
+JS_PREFERENCE_FILES += ["prefs/marionette.js"]
 
-JAR_MANIFESTS += ["jar.mn"]
 MARIONETTE_UNIT_MANIFESTS += ["harness/marionette_harness/tests/unit/unit-tests.ini"]
 MARIONETTE_WEBAPI_MANIFESTS += ["harness/marionette_harness/tests/webapi-tests.ini"]
 XPCSHELL_TESTS_MANIFESTS += ["unit.ini"]
 
 with Files("**"):
     BUG_COMPONENT = ("Testing", "Marionette")

--- a/testing/marionette/prefs/marionette.js
+++ b/testing/marionette/prefs/marionette.js
@@ -1,12 +1,19 @@
 /* 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/. */
 
+// Marionette is the remote protocol that lets OOP programs communicate
+// with, instrument, and control Gecko.
+//
+// It is included in Firefox, but not enabled by default unless the
+// --marionette flag is passed or the marionette.enabled preference is
+// set to true.
+
 // Whether or not Marionette is enabled.
 pref("marionette.enabled", false);
 
 // Port to start Marionette server on.
 pref("marionette.port", 2828);
 
 // Forces client connections to come from a loopback device.
 pref("marionette.forcelocal", true);