diff --git a/src/compositor.h b/src/compositor.h
index 06476ccf..a4292d23 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -197,7 +197,7 @@ struct weston_output {
 	int (*switch_mode)(struct weston_output *output, struct weston_mode *mode);
 
 	/* backlight values are on 0-255 range, where higher is brighter */
-	uint32_t backlight_current;
+	int32_t backlight_current;
 	void (*set_backlight)(struct weston_output *output, uint32_t value);
 	void (*set_dpms)(struct weston_output *output, enum dpms_enum level);