diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index fab970d9e3e1d111372fd2c6551c262e8eb9956d..022bacb71a7ede51571a6976830859d3f674bb71 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -150,9 +150,9 @@ mode_store(struct device *dev, struct device_attribute *attr,
 	if (!tz->ops->set_mode)
 		return -EPERM;
 
-	if (!strncmp(buf, "enabled", sizeof("enabled")))
+	if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
 		result = tz->ops->set_mode(tz, THERMAL_DEVICE_ENABLED);
-	else if (!strncmp(buf, "disabled", sizeof("disabled")))
+	else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
 		result = tz->ops->set_mode(tz, THERMAL_DEVICE_DISABLED);
 	else
 		result = -EINVAL;