diff --git a/libv4l-rockchip/libv4l-encplugin-rockchip.c b/libv4l-rockchip/libv4l-encplugin-rockchip.c
index edb652676f4ebadc12a510c39f785d75c5fb82ff..e9d2bb1743e0ad7856dc5229ff02bbc221e8ef37 100644
--- a/libv4l-rockchip/libv4l-encplugin-rockchip.c
+++ b/libv4l-rockchip/libv4l-encplugin-rockchip.c
@@ -341,6 +341,8 @@ static int ioctl_qbuf_locked(struct encoder_context *ctx, int fd,
 	if (ret)
 		return ret;
 
+	/* TODO: change this to config_store after the header is updated. */
+	buffer->reserved2 = buffer->index + 1;
 	ret = SYS_IOCTL(fd, VIDIOC_QBUF, buffer);
 	if (ret == 0)
 		ctx->can_qbuf = false;