Index: Makefile
===================================================================
--- Makefile	(revision 4520dc027de24ff86a927913cb5771a531b61ed8)
+++ Makefile	(revision 611150b5f5b45339c86cc1ebae5e1265ccdb4729)
@@ -48,4 +48,8 @@
 endif
 
+ifeq ($(CONFIG_BAT),y)
+	DEFS += -DCONFIG_BAT
+endif
+
 .PHONY: all build config distclean arch_distclean clean kernel uspace clean_kernel clean_uspace distclean_kernel distclean_uspace
 
