diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index a888893..02c6f4d 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -246,7 +246,7 @@
 			struct v4l2_dv_timings *timings);
 	int (*g_dv_timings)(struct v4l2_subdev *sd,
 			struct v4l2_dv_timings *timings);
-	int (*enum_mbus_fmt)(struct v4l2_subdev *sd, int index,
+	int (*enum_mbus_fmt)(struct v4l2_subdev *sd, unsigned int index,
 			     enum v4l2_mbus_pixelcode *code);
 	int (*g_mbus_fmt)(struct v4l2_subdev *sd,
 			  struct v4l2_mbus_framefmt *fmt);