diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index 6f8d8f9..800e0c5 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -374,7 +374,7 @@
 	if (!sscanf(buf, "%ld\n", &state))
 		return -EINVAL;
 
-	if (state < 0)
+	if ((long)state < 0)
 		return -EINVAL;
 
 	result = cdev->ops->set_cur_state(cdev, state);