diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index b29134de983b85ff2df85ba171d8e4a7f8cdac5b..d399b8b0f000a40c6c733e077eeb667a06dc02cf 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -524,8 +524,8 @@ static void serio_init_port(struct serio *serio)
 	spin_lock_init(&serio->lock);
 	mutex_init(&serio->drv_mutex);
 	device_initialize(&serio->dev);
-	dev_set_name(&serio->dev, "serio%ld",
-			(long)atomic_inc_return(&serio_no) - 1);
+	dev_set_name(&serio->dev, "serio%lu",
+		     (unsigned long)atomic_inc_return(&serio_no) - 1);
 	serio->dev.bus = &serio_bus;
 	serio->dev.release = serio_release_port;
 	serio->dev.groups = serio_device_attr_groups;