diff --git a/drivers/w1/slaves/w1_bq27000.c b/drivers/w1/slaves/w1_bq27000.c
index 52ad812fa1e7e73c8bc07545b82e967c73ff6a50..87554788fa32f963be93ab2f22103dff3f162ca5 100644
--- a/drivers/w1/slaves/w1_bq27000.c
+++ b/drivers/w1/slaves/w1_bq27000.c
@@ -31,10 +31,10 @@ static int w1_bq27000_read(struct device *dev, unsigned int reg)
 	u8 val;
 	struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev);
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->mutex);
 	w1_write_8(sl->master, HDQ_CMD_READ | reg);
 	val = w1_read_8(sl->master);
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->mutex);
 
 	return val;
 }
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 2f2e894ea0c84e23392db10c0fb4e46b25b00ab3..69075c3dfc737289023a38973ff944671de2545a 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -688,6 +688,7 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 	memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 	atomic_set(&sl->refcnt, 0);
 	init_completion(&sl->released);
+	mutex_init(&sl->mutex);
 
 	spin_lock(&w1_flock);
 	f = w1_family_registered(rn->family);
diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
index 4d012ca3f32c42a27c2ccd54b9b506907abd597e..8c8be380a98a3bda388a22284a401b7756aaa2f1 100644
--- a/drivers/w1/w1.h
+++ b/drivers/w1/w1.h
@@ -75,6 +75,7 @@ struct w1_slave
 	void			*family_data;
 	struct device		dev;
 	struct completion	released;
+	struct mutex		mutex;
 };
 
 typedef void (*w1_slave_found_callback)(struct w1_master *, u64);