diff --git a/Makefile.mk b/Makefile.mk
index 301a3bc..16b6539 100644
--- a/Makefile.mk
+++ b/Makefile.mk
@@ -99,7 +99,7 @@
 # site-local Makefile.mk must go first to override default locations (for binaries etc.)
 subdirs-y := site-local
 
-subdirs-y := src/lib src/commonlib/ src/console src/device src/acpi src/superio/common
+subdirs-y += src/lib src/commonlib/ src/console src/device src/acpi src/superio/common
 subdirs-$(CONFIG_EC_ACPI) += src/ec/intel
 subdirs-y += src/ec/acpi $(wildcard src/ec/*/*) $(wildcard src/southbridge/*/*)
 subdirs-y += $(wildcard src/soc/*) $(wildcard src/soc/*/common) $(filter-out $(wildcard src/soc/*/common),$(wildcard src/soc/*/*))