diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 28375d5..dd6e17c 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -186,7 +186,7 @@
 				      char *buf)
 {
 	struct hwmon_device_attribute *hattr = to_hwmon_attr(devattr);
-	char *s;
+	const char *s;
 	int ret;
 
 	ret = hattr->ops->read_string(dev, hattr->type, hattr->attr,
diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
index 88b6737..ceb7519 100644
--- a/include/linux/hwmon.h
+++ b/include/linux/hwmon.h
@@ -337,7 +337,7 @@
 	int (*read)(struct device *dev, enum hwmon_sensor_types type,
 		    u32 attr, int channel, long *val);
 	int (*read_string)(struct device *dev, enum hwmon_sensor_types type,
-		    u32 attr, int channel, char **str);
+		    u32 attr, int channel, const char **str);
 	int (*write)(struct device *dev, enum hwmon_sensor_types type,
 		     u32 attr, int channel, long val);
 };