diff --git a/sys/sys/backlight.h b/sys/sys/backlight.h
index 4742d40e746..697e0b6b634 100644
--- a/sys/sys/backlight.h
+++ b/sys/sys/backlight.h
@@ -30,6 +30,8 @@
 #ifndef __BACKLIGHT_H__
 #define	__BACKLIGHT_H__
 
+#include <sys/types.h>
+
 #define	BACKLIGHTMAXLEVELS 100
 
 struct backlight_props {