diff --git a/src/sound/snd_cs423x.c b/src/sound/snd_cs423x.c
index b9004454e..264171b1e 100644
--- a/src/sound/snd_cs423x.c
+++ b/src/sound/snd_cs423x.c
@@ -290,7 +290,7 @@ cs423x_write(uint16_t addr, uint8_t val, void *priv)
                         ad1848_init(&dev->ad1848, dev->ad1848_type);
                         ad1848_set_cd_audio_channel(&dev->ad1848, AD1848_AUX2);
                     }
-                    val = 0x00;
+                    val &= 0x07;
                     break;
 
                 case 1:         /* Version / Chip ID */