diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 5e40de7..f32089d 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -88,14 +88,18 @@
 BOARD :=
 endif
 
+ifeq ($(KBUILD_SRC),)
+CPPFLAGS += -I$(BOARD)/include
+else
+CPPFLAGS += -I$(srctree)/$(BOARD)/include
+endif
+
 ifneq ($(machine-y),)
 MACH  := arch/mips/mach-$(machine-y)/
 else
 MACH  :=
 endif
 
-CPPFLAGS += -I$(BOARD)/include
-
 common-y += $(BOARD) $(MACH)
 common-y += arch/mips/lib/
 common-y += arch/mips/boot/