diff --git a/b2g/app/Makefile.in b/b2g/app/Makefile.in
index 5a62154e65b5..12068016e5bb 100644
--- a/b2g/app/Makefile.in
+++ b/b2g/app/Makefile.in
@@ -29,22 +29,27 @@ endif
 
 AB_CD = $(MOZ_UI_LOCALE)
 
-AB := $(firstword $(subst -, ,$(AB_CD)))
+ifeq (zh-TW,$(AB_CD))
+LPROJ_ROOT := $(subst -,_,$(AB_CD))
+else
+LPROJ_ROOT := $(firstword $(subst -, ,$(AB_CD)))
+endif
+LPROJ := Contents/Resources/$(LPROJ_ROOT).lproj
 
 clean clobber repackage::
 	rm -rf $(DIST)/$(APP_NAME).app
 
 libs-preqs = \
   $(call mkdir_deps,$(DIST)/$(APP_NAME).app/Contents/MacOS) \
-  $(call mkdir_deps,$(DIST)/$(APP_NAME).app/Contents/Resources/$(AB).lproj) \
+  $(call mkdir_deps,$(DIST)/$(APP_NAME).app/$(LPROJ)) \
   $(NULL)
 
 .PHONY: repackage
 tools repackage:: $(libs-preqs)
 	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents $(DIST)/$(APP_NAME).app --exclude English.lproj
-	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents/Resources/English.lproj/ $(DIST)/$(APP_NAME).app/Contents/Resources/$(AB).lproj
+	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents/Resources/English.lproj/ $(DIST)/$(APP_NAME).app/$(LPROJ)
 	sed -e 's/%MOZ_APP_VERSION%/$(MOZ_APP_VERSION)/' -e 's/%MOZ_APP_NAME%/$(MOZ_APP_NAME)/' -e 's/%APP_VERSION%/$(APP_VERSION)/' -e 's/%APP_NAME%/$(APP_NAME)/' -e 's/%APP_BINARY%/$(APP_BINARY)/' $(srcdir)/macbuild/Contents/Info.plist.in > $(DIST)/$(APP_NAME).app/Contents/Info.plist
-	sed -e 's/%APP_VERSION%/$(APP_VERSION)/' -e 's/%APP_NAME%/$(APP_NAME)/' $(srcdir)/macbuild/Contents/Resources/English.lproj/InfoPlist.strings.in | iconv -f UTF-8 -t UTF-16 > $(DIST)/$(APP_NAME).app/Contents/Resources/$(AB).lproj/InfoPlist.strings
+	sed -e 's/%APP_VERSION%/$(APP_VERSION)/' -e 's/%APP_NAME%/$(APP_NAME)/' $(srcdir)/macbuild/Contents/Resources/English.lproj/InfoPlist.strings.in | iconv -f UTF-8 -t UTF-16 > $(DIST)/$(APP_NAME).app/$(LPROJ)/InfoPlist.strings
 	rsync -a --exclude 'mangle' --exclude 'shlibsign' --exclude-from='$(srcdir)/macbuild/Contents/MacOS-files.in' $(DIST)/bin/ $(DIST)/$(APP_NAME).app/Contents/Resources
 	rsync -a --include-from='$(srcdir)/macbuild/Contents/MacOS-files.in' --exclude '*' $(DIST)/bin/ $(DIST)/$(APP_NAME).app/Contents/MacOS
 ifdef LIBXUL_SDK
diff --git a/browser/app/Makefile.in b/browser/app/Makefile.in
index d1c6ebafb23b..a4f2b048b0c7 100644
--- a/browser/app/Makefile.in
+++ b/browser/app/Makefile.in
@@ -79,7 +79,12 @@ endif
 
 AB_CD = $(MOZ_UI_LOCALE)
 
-AB := $(firstword $(subst -, ,$(AB_CD)))
+ifeq (zh-TW,$(AB_CD))
+LPROJ_ROOT := $(subst -,_,$(AB_CD))
+else
+LPROJ_ROOT := $(firstword $(subst -, ,$(AB_CD)))
+endif
+LPROJ := Contents/Resources/$(LPROJ_ROOT).lproj
 
 clean clobber repackage::
 	$(RM) -r $(dist_dest)
@@ -89,11 +94,11 @@ MAC_BUNDLE_VERSION = $(shell $(PYTHON) $(srcdir)/macversion.py --version=$(MOZ_A
 .PHONY: repackage
 tools repackage:: $(PROGRAM)
 	$(MKDIR) -p $(dist_dest)/Contents/MacOS
-	$(MKDIR) -p $(dist_dest)/Contents/Resources/$(AB).lproj
+	$(MKDIR) -p $(dist_dest)/$(LPROJ)
 	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents $(dist_dest) --exclude English.lproj
-	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents/Resources/English.lproj/ $(dist_dest)/Contents/Resources/$(AB).lproj
+	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents/Resources/English.lproj/ $(dist_dest)/$(LPROJ)
 	sed -e 's/%APP_VERSION%/$(MOZ_APP_VERSION)/' -e 's/%MAC_APP_NAME%/$(MAC_APP_NAME)/' -e 's/%MOZ_MACBUNDLE_ID%/$(MOZ_MACBUNDLE_ID)/' -e 's/%MAC_BUNDLE_VERSION%/$(MAC_BUNDLE_VERSION)/' $(srcdir)/macbuild/Contents/Info.plist.in > $(dist_dest)/Contents/Info.plist
-	sed -e 's/%MAC_APP_NAME%/$(MAC_APP_NAME)/' $(srcdir)/macbuild/Contents/Resources/English.lproj/InfoPlist.strings.in | iconv -f UTF-8 -t UTF-16 > $(dist_dest)/Contents/Resources/$(AB).lproj/InfoPlist.strings
+	sed -e 's/%MAC_APP_NAME%/$(MAC_APP_NAME)/' $(srcdir)/macbuild/Contents/Resources/English.lproj/InfoPlist.strings.in | iconv -f UTF-8 -t UTF-16 > $(dist_dest)/$(LPROJ)/InfoPlist.strings
 	rsync -a --exclude-from='$(srcdir)/macbuild/Contents/MacOS-files.in' $(DIST)/bin/ $(dist_dest)/Contents/Resources
 	rsync -a --include-from='$(srcdir)/macbuild/Contents/MacOS-files.in' --exclude '*' $(DIST)/bin/ $(dist_dest)/Contents/MacOS
 	$(RM) $(dist_dest)/Contents/MacOS/$(PROGRAM)
diff --git a/browser/installer/Makefile.in b/browser/installer/Makefile.in
index 2a7a4a34dba7..04496e676c14 100644
--- a/browser/installer/Makefile.in
+++ b/browser/installer/Makefile.in
@@ -126,8 +126,13 @@ RESPATH = $(BINPATH)
 endif
 DEFINES += -DRESPATH=$(RESPATH)
 
-AB = $(firstword $(subst -, ,$(AB_CD)))
-DEFINES += -DAB=$(AB)
+LPROJ_ROOT = $(firstword $(subst -, ,$(AB_CD)))
+ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
+ifeq (zh-TW,$(AB_CD))
+LPROJ_ROOT := $(subst -,_,$(AB_CD))
+endif
+endif
+DEFINES += -DLPROJ_ROOT=$(LPROJ_ROOT)
 
 DEFINES += -DMOZ_ICU_VERSION=$(MOZ_ICU_VERSION)
 ifdef MOZ_NATIVE_ICU
diff --git a/browser/installer/package-manifest.in b/browser/installer/package-manifest.in
index 306b14895442..48e5d17b7485 100644
--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -38,7 +38,7 @@
 @APPNAME@/Contents/PkgInfo
 @RESPATH@/firefox.icns
 @RESPATH@/document.icns
-@RESPATH@/@AB@.lproj/*
+@RESPATH@/@LPROJ_ROOT@.lproj/*
 #endif
 
 [@AB_CD@]
diff --git a/toolkit/locales/l10n.mk b/toolkit/locales/l10n.mk
index 0c84430dd47a..9203fb710b51 100644
--- a/toolkit/locales/l10n.mk
+++ b/toolkit/locales/l10n.mk
@@ -32,7 +32,12 @@ run_for_effects := $(shell if test ! -d $(DIST); then $(NSINSTALL) -D $(DIST); f
 # This makefile uses variable overrides from the libs-% target to
 # build non-default locales to non-default dist/ locations. Be aware!
 
-AB = $(firstword $(subst -, ,$(AB_CD)))
+LPROJ_ROOT = $(firstword $(subst -, ,$(AB_CD)))
+ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
+ifeq (zh-TW,$(AB_CD))
+LPROJ_ROOT := $(subst -,_,$(AB_CD))
+endif
+endif
 
 # These are defaulted to be compatible with the files the wget-en-US target
 # pulls. You may override them if you provide your own files. You _must_
@@ -116,8 +121,8 @@ endif
 		$(if $(filter omni,$(MOZ_PACKAGER_FORMAT)),$(if $(NON_OMNIJAR_FILES),--non-resource $(NON_OMNIJAR_FILES)))
 
 ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
-ifneq (en,$(AB))
-	mv $(STAGEDIST)/en.lproj $(STAGEDIST)/$(AB).lproj
+ifneq (en,$(LPROJ_ROOT))
+	mv $(STAGEDIST)/en.lproj $(STAGEDIST)/$(LPROJ_ROOT).lproj
 endif
 ifdef MOZ_CRASHREPORTER
 # On Mac OS X, the crashreporter.ini file needs to be moved from under the
@@ -138,9 +143,9 @@ ifdef MAKE_COMPLETE_MAR
 	  PACKAGE_BASE_DIR='$(_ABS_DIST)/l10n-stage'
 endif
 # packaging done, undo l10n stuff
-ifneq (en,$(AB))
+ifneq (en,$(LPROJ_ROOT))
 ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
-	mv $(STAGEDIST)/$(AB).lproj $(STAGEDIST)/en.lproj
+	mv $(STAGEDIST)/$(LPROJ_ROOT).lproj $(STAGEDIST)/en.lproj
 endif
 endif
 	$(NSINSTALL) -D $(DIST)/$(PKG_PATH)