diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 470e754..018a428 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -549,7 +549,7 @@
 {
 	unsigned long x;
 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
-	if (sscanf(buf, "%ld\n", &x) == 1)
+	if (sscanf(buf, "%lu\n", &x) == 1)
 		battery->alarm = x/1000;
 	if (acpi_battery_present(battery))
 		acpi_battery_set_alarm(battery);