diff --git a/mozilla/l10n/Makefile.in b/mozilla/l10n/Makefile.in
index ff942e06a4a..f8c3e5b3e6f 100644
--- a/mozilla/l10n/Makefile.in
+++ b/mozilla/l10n/Makefile.in
@@ -22,6 +22,12 @@ srcdir		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
-DIRS	= lang
+ifdef MOZ_L10N_TOOLS
+DIRS	+= tools
+endif
+
+ifdef MOZ_L10N_LANG
+DIRS	+= lang
+endif
 
 include $(topsrcdir)/config/rules.mk