diff --git a/libavdevice/v4l.c b/libavdevice/v4l.c
index d9dc635eed..5d57a2bbdc 100644
--- a/libavdevice/v4l.c
+++ b/libavdevice/v4l.c
@@ -46,7 +46,7 @@ typedef struct {
     int gb_frame;
 } VideoData;
 
-struct {
+static const struct {
     int palette;
     int depth;
     enum PixelFormat pix_fmt;