diff --git a/sound/soc/codecs/rt5645.c b/sound/soc/codecs/rt5645.c
index d70847c9eeb0..72e7a40004ff 100644
--- a/sound/soc/codecs/rt5645.c
+++ b/sound/soc/codecs/rt5645.c
@@ -440,6 +440,7 @@ static bool rt5645_volatile_register(struct device *dev, unsigned int reg)
 
 	switch (reg) {
 	case RT5645_RESET:
+	case RT5645_PRIV_INDEX:
 	case RT5645_PRIV_DATA:
 	case RT5645_IN1_CTRL1:
 	case RT5645_IN1_CTRL2: