--- a/mail/locales/Makefile.in
+++ b/mail/locales/Makefile.in
@@ -187,21 +187,25 @@ ifeq (WINNT, $(OS_ARCH))
 	mv "$(DIST)/$(PKG_INST_PATH)$(PKG_INST_BASENAME).exe" \
 	   "$(UPLOAD_DIR)/$(PKG_INST_PATH)$(PKG_INST_BASENAME).exe"
 endif
 # Set the permissions that the folders will have in ftp once uploaded
 	chmod -vR 775 $(UPLOAD_DIR)
 
 # test target, depends on make package
 # try to repack x-test, with just toolkit/defines.inc being there
+l10n-check:: INNER_UNMAKE_PACKAGE=true
 l10n-check::
 	$(RM) -rf x-test
 	$(NSINSTALL) -D x-test/toolkit
 	echo '#define MOZ_LANG_TITLE Just testing' > x-test/toolkit/defines.inc
-	$(MAKE) installers-x-test L10NBASEDIR='$(PWD)'
+	$(MAKE) installers-x-test L10NBASEDIR='$(PWD)' \
+	    ZIP_IN='$(ZIP_IN)' WIN32_INSTALLER_IN='$(WIN32_INSTALLER_IN)' MOZ_SIMPLE_PACKAGE_NAME=
+	$(PYTHON) $(topsrcdir)/toolkit/mozapps/installer/unpack.py $(DIST)/l10n-stage/$(MOZ_PKG_DIR)$(_RESPATH)
+	cd $(DIST)/l10n-stage && test $$(cat $(MOZ_PKG_DIR)$(_RESPATH)/update.locale) = x-test
 
 ifdef MOZ_CALENDAR
 LIGHTNING_PATH=$(commtopobjdir)/calendar/lightning
 GDATA_PATH=$(commtopobjdir)/calendar/providers/gdata
 
 define run-calendar-rule
 $(MAKE) -C $(LIGHTNING_PATH) $(subst calendar-,,$@) AB_CD=$(AB_CD)
 $(MAKE) -C $(GDATA_PATH) $(subst calendar-,,$@) AB_CD=$(AB_CD)