diff --git a/modules/net-glb/url_map.tf b/modules/net-glb/url_map.tf
index dd0a67292..8e7429180 100644
--- a/modules/net-glb/url_map.tf
+++ b/modules/net-glb/url_map.tf
@@ -34,8 +34,8 @@ locals {
     && try(var.url_map_config.default_route_action.weighted_backend_services, null) == null
     && try(var.url_map_config.default_url_redirect, null) == null
     ? try(
-      google_compute_backend_bucket.bucket.0.id,
-      google_compute_backend_service.group.0.id,
+      google_compute_backend_bucket.bucket[keys(google_compute_backend_bucket.bucket)[0]].id,
+      google_compute_backend_service.group[keys(google_compute_backend_service.group)[0]].id,
       null
     )
     : null