diff --git a/locales/Makefile.in b/locales/Makefile.in
--- a/locales/Makefile.in
+++ b/locales/Makefile.in
@@ -26,42 +26,46 @@ XPI_PKGNAME            = chatzilla-$(CHA
 # 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)))
 override AB_CD = en-US
 endif
 
-DEFINES += -DAB_CD=$(AB_CD) \
-           -DSEAMONKEY_MAXVERSION=$(SEAMONKEY_MAXVERSION) \
-           -DFIREFOX_MAXVERSION=$(FIREFOX_MAXVERSION) \
-           $(NULL)
-
 ifneq (en-US,$(AB_CD))
 XPI_NAME               = chatzilla-$(AB_CD)
 INSTALL_EXTENSION_ID   = langpack-$(AB_CD)@chatzilla.mozilla.org
 XPI_PKGNAME            = chatzilla-$(CHATZILLA_VERSION).$(AB_CD)
-DIST_FILES             = generic/install.rdf
-XULPPFLAGS += \
-    -I$(call EXPAND_LOCALE_SRCDIR,toolkit/locales)/defines.inc \
-    -I$(LOCALE_SRCDIR)/defines.inc \
-    $(NULL)
 endif
 
-DEFINES += -DINSTALL_EXTENSION_ID="$(INSTALL_EXTENSION_ID)"
-DEFINES += -DCHATZILLA_VERSION=$(CHATZILLA_VERSION)
-DEFINES += -DCHATZILLA_BASE_VERSION=$(CHATZILLA_BASE_VERSION)
+DEFINES += -DAB_CD=$(AB_CD) \
+           -DSEAMONKEY_MAXVERSION=$(SEAMONKEY_MAXVERSION) \
+           -DFIREFOX_MAXVERSION=$(FIREFOX_MAXVERSION) \
+           -DINSTALL_EXTENSION_ID="$(INSTALL_EXTENSION_ID)" \
+           -DCHATZILLA_VERSION=$(CHATZILLA_VERSION) \
+           -DCHATZILLA_BASE_VERSION=$(CHATZILLA_BASE_VERSION) \
+           $(NULL)
+
+APP_DEFINES = $(firstword $(wildcard $(LOCALE_SRCDIR)/defines.inc) \
+                          $(srcdir)/en-US/defines.inc)
+
+TK_DEFINES = $(firstword \
+             $(wildcard $(call EXPAND_LOCALE_SRCDIR,toolkit/locales)/defines.inc) \
+             $(MOZILLA_DIR)/toolkit/locales/en-US/defines.inc)
 
 include $(topsrcdir)/config/rules.mk
 
 ifneq (en-US,$(AB_CD))
 libs realchrome::
 	@echo "Comparing $(AB_CD) to en-US"
 	@$(PERL) $(topsrcdir)/toolkit/locales/compare-locales.pl $(srcdir)/en-US $(LOCALE_SRCDIR)
+	$(call py_action,preprocessor,$(DEFINES) $(ACDEFINES) \
+	  -DTK_DEFINES=$(TK_DEFINES) -DAPP_DEFINES=$(APP_DEFINES) \
+	  $(srcdir)/generic/install.rdf -o $(DIST)/xpi-stage/$(XPI_NAME)/install.rdf)
 endif
 
 libs-%: AB_CD=$*
 libs-%:
 	# XXX: it would be nice if we could just do nothing if no langpack is being done
 	#  currently, we just go and (re)build en-US if called with a non-supported locale
 	$(MAKE) libs AB_CD=$*
 
diff --git a/locales/generic/install.rdf b/locales/generic/install.rdf
--- a/locales/generic/install.rdf
+++ b/locales/generic/install.rdf
@@ -1,15 +1,20 @@
 <?xml version="1.0"?>
 <!-- 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/. -->
 
 #filter substitution
 
+#ifndef IRC_STANDALONE_BUILD
+#include @TK_DEFINES@
+#include @APP_DEFINES@
+#endif
+
 <RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
      xmlns:em="http://www.mozilla.org/2004/em-rdf#">
   <Description about="urn:mozilla:install-manifest"
                em:id="@INSTALL_EXTENSION_ID@"
                em:name="ChatZilla @MOZ_LANG_TITLE@ Language Pack"
                em:version="@CHATZILLA_VERSION@"
                em:type="8"
                em:creator="@MOZ_LANGPACK_CREATOR@"
diff --git a/xpi/makexpi.py b/xpi/makexpi.py
--- a/xpi/makexpi.py
+++ b/xpi/makexpi.py
@@ -17,18 +17,18 @@ import sys
 import shutil
 import re
 import zipfile
 from os.path import join as joinpath
 
 # Set up settings and paths for finding files.
 pwd = os.path.dirname(__file__)
 
-ffversion = '44.*'
-smversion = '2.41.*'
+ffversion = '45.*'
+smversion = '2.42.*'
 
 if pwd == '':
     pwd = os.getcwd()
 else:
     os.chdir(pwd)
 
 def getenv(var, default, dir=False, check=False):
     """
@@ -379,17 +379,18 @@ def do_build_locale():
     progress_mkdir(joinpath(xpiroot, 'chrome'))
     print '               done'
 
     progress_echo('  Checking JAR structure')
     progress_mkdir(jarroot)
     print '                done'
 
     progress_echo('  Updating extension files')
-    progress_preprocess([joinpath(localedir, locale, 'defines.inc'), joinpath(localedir, 'generic', 'install.rdf')], joinpath(xpiroot, 'install.rdf.pp'), {'CHATZILLA_VERSION': version, 'CHATZILLA_BASE_VERSION': version, 'AB_CD': locale, 'INSTALL_EXTENSION_ID': 'langpack-%s@chatzilla.mozilla.org' % locale, 'MOZ_LANG_TITLE': locale, 'FIREFOX_MAXVERSION': ffversion, 'SEAMONKEY_MAXVERSION': smversion})
+    progress_preprocess([joinpath(localedir, locale, 'defines.inc'), joinpath(localedir, 'generic', 'install.rdf')], joinpath(xpiroot, 'install.rdf.pp'),
+             {'IRC_STANDALONE_BUILD': '1', 'CHATZILLA_VERSION': version, 'CHATZILLA_BASE_VERSION': version, 'AB_CD': locale, 'INSTALL_EXTENSION_ID': 'langpack-%s@chatzilla.mozilla.org' % locale, 'MOZ_LANG_TITLE': locale, 'FIREFOX_MAXVERSION': ffversion, 'SEAMONKEY_MAXVERSION': smversion})
     progress_sed(joinpath(xpiroot, 'install.rdf.pp'), joinpath(xpiroot, 'install.rdf'), ('chatzilla.jar', 'chatzilla-%s.jar' % locale))
     progress_rm(joinpath(xpiroot, 'install.rdf.pp'))
     print '    done'
 
     progress_echo('  Constructing JAR package')
     jm = progress_jarmaker()
     progress_preprocess(joinpath(localedir, 'jar.mn'), joinpath(localedir, 'jar.mn.pp'), {'AB_CD': locale})
     jm.pp.context['AB_CD'] = locale