--- a/browser/locales/Makefile.in
+++ b/browser/locales/Makefile.in
@@ -104,16 +104,17 @@ endif
 ifndef RELEASE_OR_BETA
 	@$(MAKE) -C ../extensions/presentation/locale AB_CD=$* XPI_NAME=locale-$*
 endif
 ifneq '$(or $(MOZ_DEV_EDITION),$(NIGHTLY_BUILD))' ''
 	@$(MAKE) -C ../extensions/webcompat-reporter/locales AB_CD=$* XPI_NAME=locale-$*
 endif
 	@$(MAKE) -C ../../intl/locales AB_CD=$* XPI_NAME=locale-$*
 	@$(MAKE) -C ../../devtools/client/locales AB_CD=$* XPI_NAME=locale-$* XPI_ROOT_APPID='$(XPI_ROOT_APPID)'
+	@$(MAKE) -C ../../devtools/shim/locales AB_CD=$* XPI_NAME=locale-$* XPI_ROOT_APPID='$(XPI_ROOT_APPID)'
 	@$(MAKE) -B searchplugins AB_CD=$* XPI_NAME=locale-$*
 	@$(MAKE) libs AB_CD=$* XPI_NAME=locale-$* PREF_DIR=$(PREF_DIR)
 	@$(MAKE) -C $(DEPTH)/$(MOZ_BRANDING_DIRECTORY)/locales AB_CD=$* XPI_NAME=locale-$*
 
 chrome-%: AB_CD=$*
 chrome-%: IS_LANGUAGE_REPACK=1
 chrome-%:
 	$(if $(filter en-US,$(AB_CD)),, @$(MAKE) merge-$*)
@@ -124,16 +125,17 @@ ifndef RELEASE_OR_BETA
 	@$(MAKE) -C ../extensions/formautofill/locales chrome AB_CD=$*
 endif
 	@$(MAKE) -C ../extensions/pocket/locale chrome AB_CD=$*
 ifndef RELEASE_OR_BETA
 	@$(MAKE) -C ../extensions/presentation/locale chrome AB_CD=$*
 endif
 	@$(MAKE) -C ../../intl/locales chrome AB_CD=$*
 	@$(MAKE) -C ../../devtools/client/locales chrome AB_CD=$*
+	@$(MAKE) -C ../../devtools/shim/locales chrome AB_CD=$*
 	@$(MAKE) chrome AB_CD=$*
 	@$(MAKE) -C $(DEPTH)/$(MOZ_BRANDING_DIRECTORY)/locales chrome AB_CD=$*
 ifdef NIGHTLY_BUILD
 	@$(MAKE) -C ../extensions/webcompat-reporter/locales chrome AB_CD=$*
 endif
 
 repackage-win32-installer: WIN32_INSTALLER_OUT=$(ABS_DIST)/$(PKG_INST_PATH)$(PKG_INST_BASENAME).exe
 repackage-win32-installer: $(call ESCAPE_WILDCARD,$(WIN32_INSTALLER_IN)) $(SUBMAKEFILES) libs-$(AB_CD)

--- a/browser/locales/filter.py
+++ b/browser/locales/filter.py
@@ -1,17 +1,17 @@
 # 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/.
 
 def test(mod, path, entity = None):
   import re
   # ignore anything but Firefox
   if mod not in ("netwerk", "dom", "toolkit", "security/manager",
-                 "devtools/client", "devtools/shared",
+                 "devtools/client", "devtools/shared", "devtools/shim",
                  "browser",
                  "browser/extensions/onboarding",
                  "browser/extensions/webcompat-reporter",
                  "extensions/spellcheck",
                  "other-licenses/branding/firefox",
                  "browser/branding/official",
                  "services/sync"):
     return "ignore"

--- a/browser/locales/l10n.ini
+++ b/browser/locales/l10n.ini
@@ -6,16 +6,17 @@
 depth = ../..
 all = browser/locales/all-locales
 
 [compare]
 dirs = browser
      other-licenses/branding/firefox
      browser/branding/official
      devtools/client
+     devtools/shim
      browser/extensions/onboarding
      browser/extensions/webcompat-reporter
 
 [includes]
 # non-central apps might want to use %(topsrcdir)s here, or other vars
 # RFE: that needs to be supported by compare-locales, too, though
 toolkit = toolkit/locales/l10n.ini
 services_sync = services/sync/locales/l10n.ini

--- a/browser/locales/l10n.toml
+++ b/browser/locales/l10n.toml
@@ -132,16 +132,20 @@ locales = [
 
 
 [[includes]]
     path = "toolkit/locales/l10n.toml"
 
 [[includes]]
     path = "devtools/client/locales/l10n.toml"
 
+[[paths]]
+    reference = "devtools/shim/locales/en-US/**"
+    l10n = "{l}devtools/shim/**"
+
 # Filters
 # The filters below are evaluated one after the other, in the given order.
 # Enter a combination of path as in the localization, key, and an action,
 # to change the default behavior of compare-locales and l10n merge.
 #
 # For browser/locales/en-US/chrome/browser/foo.properties,
 # path would be {l}browser/chrome/browser/foo.properties
 # key: the key/id of the entity

--- a/devtools/chrome.manifest
+++ b/devtools/chrome.manifest
@@ -1,8 +1,9 @@
 content devtools client/
 skin devtools classic/1.0 client/themes/
 resource devtools .
 locale devtools en-US client/locales/en-US/
 locale devtools-shared en-US shared/locales/en-US/
+locale devtools-shim en-US shim/locales/en-US/
 
 content webide client/webide/content/
 skin webide classic/1.0 client/webide/themes/

new file mode 100644
--- /dev/null
+++ b/devtools/shim/locales/jar.mn
@@ -0,0 +1,8 @@
+#filter substitution
+# 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/.
+
+@AB_CD@.jar:
+%   locale devtools-shim @AB_CD@ %locale/@AB_CD@/devtools/shim/
+    locale/@AB_CD@/devtools/shim/ (%*)

new file mode 100644
--- /dev/null
+++ b/devtools/shim/locales/moz.build
@@ -0,0 +1,7 @@
+# -*- 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']

--- a/devtools/shim/moz.build
+++ b/devtools/shim/moz.build
@@ -14,9 +14,13 @@ JS_PREFERENCE_PP_FILES += [
 if CONFIG['MOZ_DEVTOOLS'] != 'server':
     EXTRA_COMPONENTS += [
         'aboutdebugging-registration.js',
         'aboutdebugging.manifest',
         'devtools-startup.js',
         'devtools-startup.manifest',
     ]
 
+    DIRS += [
+      'locales',
+    ]
+
 XPCSHELL_TESTS_MANIFESTS += ['tests/unit/xpcshell.ini']