--- a/build/Makefile.in
+++ b/build/Makefile.in
@@ -1,16 +1,13 @@
 #
 # 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_RCS_MK := 1
-include $(topsrcdir)/config/makefiles/makeutils.mk
-
 ifdef MOZ_APP_BASENAME
 APP_INI_DEPS = $(topsrcdir)/config/milestone.txt
 
 APP_INI_DEPS += $(DEPTH)/config/autoconf.mk
 endif
 
 # NOTE: Keep .gdbinit in the topsrcdir for people who run gdb from the topsrcdir.
 # needs to be absolute to be distinct from $(topsrcdir)/.gdbinit

--- a/toolkit/mozapps/installer/package-name.mk
+++ b/toolkit/mozapps/installer/package-name.mk
@@ -142,21 +142,16 @@ TALOS_PACKAGE = $(PKG_BASENAME).talos.te
 GTEST_PACKAGE = $(PKG_BASENAME).gtest.tests.zip
 
 ifneq (,$(wildcard $(DIST)/bin/application.ini))
 BUILDID = $(shell $(PYTHON) $(MOZILLA_DIR)/config/printconfigsetting.py $(DIST)/bin/application.ini App BuildID)
 else
 BUILDID = $(shell $(PYTHON) $(MOZILLA_DIR)/config/printconfigsetting.py $(DIST)/bin/platform.ini Build BuildID)
 endif
 
-ifndef INCLUDED_RCS_MK
-  USE_RCS_MK := 1
-  include $(MOZILLA_DIR)/config/makefiles/makeutils.mk
-endif
-
 MOZ_SOURCESTAMP_FILE = $(DIST)/$(PKG_PATH)/$(MOZ_INFO_BASENAME).txt
 MOZ_BUILDINFO_FILE = $(DIST)/$(PKG_PATH)/$(MOZ_INFO_BASENAME).json
 MOZ_BUILDID_INFO_TXT_FILE = $(DIST)/$(PKG_PATH)/$(MOZ_INFO_BASENAME)_info.txt
 MOZ_MOZINFO_FILE = $(DIST)/$(PKG_PATH)/$(MOZ_INFO_BASENAME).mozinfo.json
 MOZ_TEST_PACKAGES_FILE = $(DIST)/$(PKG_PATH)/$(PKG_BASENAME).test_packages.json
 
 # JavaScript Shell
 ifdef MOZ_SIMPLE_PACKAGE_NAME