diff --git a/Makefile b/Makefile
index ec0f95b..d942ee3 100644
--- a/Makefile
+++ b/Makefile
@@ -13,6 +13,8 @@
 objk := $(objutil)/kconfig
 absobj := $(abspath $(obj))
 
+additional-dirs :=
+
 VBOOT_HOST_BUILD ?= $(abspath $(objutil)/vboot_lib)
 
 COREBOOT_EXPORTS := COREBOOT_EXPORTS