diff --git a/Makefile.lib b/Makefile.lib
index 9e779c39..503ffe7e 100644
--- a/Makefile.lib
+++ b/Makefile.lib
@@ -98,9 +98,15 @@ ifdef INCLUDE_ALL
 ifdef SUBDIRS-no
 SUBDIRS += $(SUBDIRS-no)
 endif
+ifdef SUBDIRS-
+SUBDIRS += $(SUBDIRS-)
+endif
 ifdef OBJS-no
 OBJS += $(OBJS-no)
 endif
+ifdef OBJS-
+OBJS += $(OBJS-)
+endif
 
 endif