diff --git a/Makefile.in b/Makefile.in
--- a/Makefile.in
+++ b/Makefile.in
@@ -12,17 +12,16 @@ include $(DEPTH)/config/autoconf.mk
 
 PACKAGE_FILE = chatzilla.pkg
 
 DIST_FILES = xpi/resources/install.rdf
 
 CHATZILLA_VERSION=$(shell grep "const __cz_version" "$(srcdir)/xul/content/static.js" | sed "s|.*\"\([^\"]\{1,\}\)\".*|\1|")
 
 XPI_NAME               = chatzilla
-USE_EXTENSION_MANIFEST = 1
 INSTALL_EXTENSION_ID   = {59c81df5-4b7a-477b-912d-4e0fdf64e5f2}
 XPI_PKGNAME            = chatzilla-$(CHATZILLA_VERSION)
 
 # include config.mk before using the AB_CD var it sets in an if statement
 include $(topsrcdir)/config/config.mk
 
 # always build en-US locale, add build locale if supported
 BUILD_LOCALES = en-US
diff --git a/ff/Makefile.in b/ff/Makefile.in
--- a/ff/Makefile.in
+++ b/ff/Makefile.in
@@ -7,13 +7,12 @@ topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
 CHATZILLA_VERSION=$(shell grep "const __cz_version" "$(srcdir)/../xul/content/static.js" | sed "s|.*\"\([^\"]\{1,\}\)\".*|\1|")
 
 XPI_NAME               = chatzilla
-USE_EXTENSION_MANIFEST = 1
 INSTALL_EXTENSION_ID   = {59c81df5-4b7a-477b-912d-4e0fdf64e5f2}
 XPI_PKGNAME            = chatzilla-$(CHATZILLA_VERSION)
 
 include $(topsrcdir)/config/rules.mk
diff --git a/ff/moz.build b/ff/moz.build
--- a/ff/moz.build
+++ b/ff/moz.build
@@ -1,6 +1,8 @@
 # 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']
+
+USE_EXTENSION_MANIFEST = True
diff --git a/locales/Makefile.in b/locales/Makefile.in
--- a/locales/Makefile.in
+++ b/locales/Makefile.in
@@ -13,17 +13,16 @@ relativesrcdir = extensions/irc/locales
 EXTERNALLY_MANAGED_MAKE_FILE := 1
 STANDALONE_MAKEFILE := 1
 JAR_MANIFEST := $(srcdir)/jar.mn
 
 CHATZILLA_VERSION=$(shell grep "const __cz_version" "$(srcdir)/../xul/content/static.js" | sed "s|.*\"\([^\"]\{1,\}\)\".*|\1|")
 CHATZILLA_BASE_VERSION=$(shell echo "$(CHATZILLA_VERSION)" | sed "s|\([0-9]\{1,\}\.[0-9]\{1,\}\.[0-9]\{1,\}\).*|\1|")
 
 XPI_NAME               = chatzilla
-USE_EXTENSION_MANIFEST = 1
 INSTALL_EXTENSION_ID   = {59c81df5-4b7a-477b-912d-4e0fdf64e5f2}
 XPI_PKGNAME            = chatzilla-$(CHATZILLA_VERSION)
 
 # include config.mk before we override the AB_CD var it sets
 include $(topsrcdir)/config/config.mk
 
 # if the wanted language is not in all-locales, fall back to en-US
 ifeq (,$(filter $(AB_CD),$(shell cat $(srcdir)/all-locales)))
diff --git a/locales/moz.build b/locales/moz.build
--- a/locales/moz.build
+++ b/locales/moz.build
@@ -1,5 +1,6 @@
 # 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/.
 
+USE_EXTENSION_MANIFEST = True
diff --git a/moz.build b/moz.build
--- a/moz.build
+++ b/moz.build
@@ -5,16 +5,17 @@
 
 DIRS += [
     'ff',
     'sm',
 ]
 
 CONFIGURE_SUBST_FILES += ['locales/Makefile']
 NO_JS_MANIFEST = True
+USE_EXTENSION_MANIFEST = True
 
 XPI_NAME = 'chatzilla'
 export('XPI_NAME')
 
 JAR_MANIFESTS += ['jar.mn']
 
 EXTRA_COMPONENTS += [
     'js/lib/chatzilla-service.js',
diff --git a/sm/Makefile.in b/sm/Makefile.in
--- a/sm/Makefile.in
+++ b/sm/Makefile.in
@@ -7,13 +7,12 @@ topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
 CHATZILLA_VERSION=$(shell grep "const __cz_version" "$(srcdir)/../xul/content/static.js" | sed "s|.*\"\([^\"]\{1,\}\)\".*|\1|")
 
 XPI_NAME               = chatzilla
-USE_EXTENSION_MANIFEST = 1
 INSTALL_EXTENSION_ID   = {59c81df5-4b7a-477b-912d-4e0fdf64e5f2}
 XPI_PKGNAME            = chatzilla-$(CHATZILLA_VERSION)
 
 include $(topsrcdir)/config/rules.mk
diff --git a/sm/moz.build b/sm/moz.build
--- a/sm/moz.build
+++ b/sm/moz.build
@@ -1,6 +1,8 @@
 # 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']
+
+USE_EXTENSION_MANIFEST = True