diff --git a/sys/modules/gpio/gpioaei/Makefile b/sys/modules/gpio/gpioaei/Makefile
index 514dcd80a35e..8f856af48eb7 100644
--- a/sys/modules/gpio/gpioaei/Makefile
+++ b/sys/modules/gpio/gpioaei/Makefile
@@ -1,14 +1,15 @@
 .PATH:	${SRCTOP}/sys/dev/gpio/
 
 KMOD=	gpioaei
 SRCS=	gpioaei.c
 
 SRCS+=	\
+	acpi_if.h \
 	bus_if.h \
 	device_if.h \
 	gpio_if.h \
 	gpiobus_if.h
 
 CFLAGS+=  -I. -I${SRCTOP}/sys/dev/gpio/
 
 .include <bsd.kmod.mk>