--- a/devtools/client/shims/moz.build
+++ b/devtools/client/shims/moz.build
@@ -6,13 +6,8 @@
 
 # Unlike most DevTools build files, this file does not use DevToolsModules
 # because these files are here for add-on compatibility, and so they must be
 # installed to previously defined locations.
 
 EXTRA_JS_MODULES.devtools += [
     'gDevTools.jsm',
 ]
-
-# Extra compatibility layer for transitional URLs used for part of 44 cycle
-EXTRA_JS_MODULES.devtools.client.framework += [
-    'gDevTools.jsm',
-]

--- a/devtools/shared/apps/moz.build
+++ b/devtools/shared/apps/moz.build
@@ -1,10 +1,9 @@
 # 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/.
 
 DevToolsModules(
     'app-actor-front.js',
-    'Devices.jsm',
-    'Simulator.jsm'
+    'Devices.jsm'
 )

deleted file mode 100644
--- a/devtools/shared/shims/Simulator.jsm
+++ /dev/null
@@ -1,34 +0,0 @@
-/* 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";
-
-/**
- * This file only exists to support add-ons which import this module at a
- * specific path.
- */
-
-const Cu = Components.utils;
-
-const { Services } = Cu.import("resource://gre/modules/Services.jsm", {});
-
-const WARNING_PREF = "devtools.migration.warnings";
-if (Services.prefs.getBoolPref(WARNING_PREF)) {
-  const { Deprecated } = Cu.import("resource://gre/modules/Deprecated.jsm", {});
-  Deprecated.warning("This path to Simulator.jsm is deprecated.  Please use " +
-                     "Cu.import(\"resource://devtools/shared/" +
-                     "apps/Simulator.jsm\") to load this module.",
-                     "https://bugzil.la/912121");
-}
-
-this.EXPORTED_SYMBOLS = [
-  "Simulator",
-];
-
-const module =
-  Cu.import("resource://devtools/shared/apps/Simulator.jsm", {});
-
-for (let symbol of this.EXPORTED_SYMBOLS) {
-  this[symbol] = module[symbol];
-}

--- a/devtools/shared/shims/moz.build
+++ b/devtools/shared/shims/moz.build
@@ -12,20 +12,14 @@
 # /toolkit modules.  Disable any DIST_SUBDIR from parent files here.
 DIST_SUBDIR = ''
 
 EXTRA_JS_MODULES.devtools += [
     'Console.jsm',
     'dbg-client.jsm',
     'event-emitter.js',
     'Loader.jsm',
-    'Simulator.jsm',
 ]
 
 # Extra compatibility layer for transitional URLs used for part of 44 cycle
 EXTRA_JS_MODULES.devtools.shared += [
-    'Console.jsm',
     'Loader.jsm',
 ]
-
-EXTRA_JS_MODULES.devtools.shared.apps += [
-    'Simulator.jsm',
-]