diff --git a/mozilla/Makefile.in b/mozilla/Makefile.in
index eeb2cb0ad38..bffcae1260b 100644
--- a/mozilla/Makefile.in
+++ b/mozilla/Makefile.in
@@ -82,6 +82,10 @@ DIRS +=				\
 
 DIRS += xpfe
 
+ifdef MOZ_MAIL_NEWS
+DIRS += mailnews
+endif
+
 include $(topsrcdir)/config/config.mk
 
 include $(topsrcdir)/config/rules.mk