Index: head/sys/modules/rpi_ft5406/Makefile
===================================================================
--- head/sys/modules/rpi_ft5406/Makefile	(revision 308580)
+++ head/sys/modules/rpi_ft5406/Makefile	(revision 308581)
@@ -1,10 +1,10 @@
 # $FreeBSD$
 
 .PATH: ${.CURDIR}/../../arm/broadcom/bcm2835/
 
 KMOD=	rpi_ft5406
 SRCS=	bcm2835_ft5406.c
 
-SRCS+= bus_if.h device_if.h ofw_bus_if.h
+SRCS+= bus_if.h device_if.h mbox_if.h ofw_bus_if.h
 
 .include <bsd.kmod.mk>