diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c
index b9211b42f6e9..b115ed815db9 100644
--- a/sound/soc/codecs/wm8731.c
+++ b/sound/soc/codecs/wm8731.c
@@ -717,6 +717,8 @@ static int wm8731_i2c_probe(struct i2c_client *i2c,
 	if (wm8731 == NULL)
 		return -ENOMEM;
 
+	mutex_init(&wm8731->lock);
+
 	wm8731->regmap = devm_regmap_init_i2c(i2c, &wm8731_regmap);
 	if (IS_ERR(wm8731->regmap)) {
 		ret = PTR_ERR(wm8731->regmap);