diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c
index 5c1e9ea43123..ca28183f4d13 100644
--- a/drivers/acpi/acpi_watchdog.c
+++ b/drivers/acpi/acpi_watchdog.c
@@ -151,11 +151,7 @@ void __init acpi_watchdog_init(void)
 		found = false;
 		resource_list_for_each_entry(rentry, &resource_list) {
 			if (rentry->res->flags == res.flags &&
-			    resource_overlaps(rentry->res, &res)) {
-				if (res.start < rentry->res->start)
-					rentry->res->start = res.start;
-				if (res.end > rentry->res->end)
-					rentry->res->end = res.end;
+			    resource_union(rentry->res, &res, rentry->res)) {
 				found = true;
 				break;
 			}