.put = snd_gf1_pcm_volume_put
 };
 
-static struct snd_pcm_ops snd_gf1_pcm_playback_ops = {
+static const struct snd_pcm_ops snd_gf1_pcm_playback_ops = {
        .open =         snd_gf1_pcm_playback_open,
        .close =        snd_gf1_pcm_playback_close,
        .ioctl =        snd_pcm_lib_ioctl,
        .fill_silence = snd_gf1_pcm_playback_silence,
 };
 
-static struct snd_pcm_ops snd_gf1_pcm_capture_ops = {
+static const struct snd_pcm_ops snd_gf1_pcm_capture_ops = {
        .open =         snd_gf1_pcm_capture_open,
        .close =        snd_gf1_pcm_capture_close,
        .ioctl =        snd_pcm_lib_ioctl,