diff --git a/hosts/backup-4/configuration.nix b/hosts/backup-4/configuration.nix
index abcc0f1..2200526 100644
--- a/hosts/backup-4/configuration.nix
+++ b/hosts/backup-4/configuration.nix
@@ -15,8 +15,18 @@
   boot.loader.grub.device = "/dev/vda";
 
   networking.useDHCP = false;
-  networking.interfaces.ens18.ipv6.addresses = [ { address = "2001:638:904:ffcb::c"; prefixLength = 64; } ];
-  networking.defaultGateway6 = { address = "2001:638:904:ffcb::1"; interface = "ens18"; };
+  systemd.network.enable = true;
+
+  systemd.network.networks."10-wan" = {
+    matchConfig.Name = "ens18";
+    address = [
+      "2001:638:904:ffcb::c/64"
+    ];
+    routes = [
+      { Gateway = "2001:638:904:ffcb::1"; }
+    ];
+    linkConfig.RequiredForOnline = "routable";
+  };
 
   services.nginx.enable = true;