--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -376,16 +376,18 @@
 @RESPATH@/browser/components/WebContentConverter.js
 @RESPATH@/browser/components/BrowserComponents.manifest
 @RESPATH@/browser/components/nsBrowserContentHandler.js
 @RESPATH@/browser/components/nsBrowserGlue.js
 @RESPATH@/browser/components/nsSetDefaultBrowser.manifest
 @RESPATH@/browser/components/nsSetDefaultBrowser.js
 @RESPATH@/browser/components/devtools-startup.manifest
 @RESPATH@/browser/components/devtools-startup.js
+@RESPATH@/browser/components/aboutdebugging-registration.js
+@RESPATH@/browser/components/aboutdebugging.manifest
 @RESPATH@/browser/components/webideCli.js
 @RESPATH@/browser/components/webideComponents.manifest
 @RESPATH@/browser/components/Experiments.manifest
 @RESPATH@/browser/components/ExperimentsService.js
 @RESPATH@/browser/components/browser-newtab.xpt
 @RESPATH@/browser/components/aboutNewTabService.js
 @RESPATH@/browser/components/NewTabComponents.manifest
 @RESPATH@/components/Downloads.manifest

new file mode 100644
--- /dev/null
+++ b/devtools/shim/aboutdebugging-registration.js
@@ -0,0 +1,45 @@
+/* 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/. */
+
+"use strict";
+
+// Register the about:debugging URL, that allows to debug various targets such as addons,
+// workers and tabs by launching a dedicated DevTools toolbox for the selected target.
+// If DevTools are not installed, this about page will display a shim landing page
+// encouraging the user to download and install DevTools.
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+const { XPCOMUtils } = Cu.import("resource://gre/modules/XPCOMUtils.jsm", {});
+const { Services } = Cu.import("resource://gre/modules/Services.jsm", {});
+
+const { nsIAboutModule } = Ci;
+
+function AboutDebugging() {}
+
+AboutDebugging.prototype = {
+  uri: Services.io.newURI("chrome://devtools/content/aboutdebugging/aboutdebugging.xhtml"),
+  classDescription: "about:debugging",
+  classID: Components.ID("1060afaf-dc9e-43da-8646-23a2faf48493"),
+  contractID: "@mozilla.org/network/protocol/about;1?what=debugging",
+
+  QueryInterface: XPCOMUtils.generateQI([nsIAboutModule]),
+
+  newChannel: function (uri, loadInfo) {
+    let chan = Services.io.newChannelFromURIWithLoadInfo(
+      this.uri,
+      loadInfo
+    );
+    chan.owner = Services.scriptSecurityManager.getSystemPrincipal();
+    return chan;
+  },
+
+  getURIFlags: function (uri) {
+    return nsIAboutModule.ALLOW_SCRIPT;
+  }
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([
+  AboutDebugging
+]);

new file mode 100644
--- /dev/null
+++ b/devtools/shim/aboutdebugging.manifest
@@ -0,0 +1,2 @@
+component {1060afaf-dc9e-43da-8646-23a2faf48493} aboutdebugging-registration.js
+contract @mozilla.org/network/protocol/about;1?what=debugging {1060afaf-dc9e-43da-8646-23a2faf48493}
\ No newline at end of file

--- a/devtools/shim/moz.build
+++ b/devtools/shim/moz.build
@@ -1,9 +1,16 @@
 # -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # 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/.
 
 JAR_MANIFESTS += ['jar.mn']
 
+# Register the about:debugging page only for 'addon' and 'all' builds.
+if CONFIG['MOZ_DEVTOOLS'] != 'server':
+    EXTRA_COMPONENTS += [
+        'aboutdebugging-registration.js',
+        'aboutdebugging.manifest',
+    ]
+
 XPCSHELL_TESTS_MANIFESTS += ['tests/unit/xpcshell.ini']

--- a/docshell/base/nsAboutRedirector.cpp
+++ b/docshell/base/nsAboutRedirector.cpp
@@ -51,22 +51,16 @@ static const RedirEntry kRedirMap[] = {
   { "config", "chrome://global/content/config.xul", 0 },
 #ifdef MOZ_CRASHREPORTER
   { "crashes", "chrome://global/content/crashes.xhtml", 0 },
 #endif
   {
     "credits", "https://www.mozilla.org/credits/",
     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT
   },
-#ifdef MOZ_DEVTOOLS_ALL
-  {
-    "debugging", "chrome://devtools/content/aboutdebugging/aboutdebugging.xhtml",
-    nsIAboutModule::ALLOW_SCRIPT
-  },
-#endif
   {
     "license", "chrome://global/content/license.html",
     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT |
       nsIAboutModule::MAKE_LINKABLE
   },
   {
     "logo", "chrome://branding/content/about.png",
     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT |

--- a/docshell/build/nsDocShellModule.cpp
+++ b/docshell/build/nsDocShellModule.cpp
@@ -172,19 +172,16 @@ const mozilla::Module::ContractIDEntry k
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "addons", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "buildconfig", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "checkerboard", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "config", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
 #ifdef MOZ_CRASHREPORTER
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "crashes", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
 #endif
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "credits", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
-#ifdef MOZ_DEVTOOLS_ALL
-  { NS_ABOUT_MODULE_CONTRACTID_PREFIX "debugging", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
-#endif
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "license", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "logo", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "memory", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "mozilla", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "neterror", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "networking", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "newaddon", &kNS_ABOUT_REDIRECTOR_MODULE_CID },
   { NS_ABOUT_MODULE_CONTRACTID_PREFIX "performance", &kNS_ABOUT_REDIRECTOR_MODULE_CID },