diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 7de99dfd11c89ae4335eb910ba57b142e71c562b..2c8dff9f77da13396b0d02207e15d486ddbd5d4e 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -171,7 +171,7 @@ static ssize_t w1_therm_read(struct device *device,
 	int i, max_trying = 10;
 	ssize_t c = PAGE_SIZE;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&dev->mutex);
 
 	memset(rom, 0, sizeof(rom));