diff --git a/modules/flake-parts/nixosConfigurations.linux-builder-01/configuration.nix b/modules/flake-parts/nixosConfigurations.linux-builder-01/configuration.nix
index 2b65342..76e9b57 100644
--- a/modules/flake-parts/nixosConfigurations.linux-builder-01/configuration.nix
+++ b/modules/flake-parts/nixosConfigurations.linux-builder-01/configuration.nix
@@ -31,9 +31,19 @@
     (self + "/modules/nixos/shared-monitoring-clients.nix")
   ];
 
-  networking.hostName = "linux-builder-01"; # Define your hostname.
+  passthru = {
+    fqdn = "${config.passthru.hostName}.${config.passthru.domain}";
 
-  hostName = "95.217.193.35";
+    domain = self.specialArgs.infraDomain;
+    hostName = "linux-builder-01"; # Define your hostname.
+
+    primaryIpv4 = "95.217.193.35";
+  };
+
+  networking = {
+    inherit (config.passthru) hostName domain;
+  };
+  hostName = config.passthru.primaryIpv4;
 
   nix.settings.max-jobs = 32;
 
diff --git a/modules/flake-parts/nixosConfigurations.sbd-0.main.infra.holo.host/configuration.nix b/modules/flake-parts/nixosConfigurations.sbd-0.main.infra.holo.host/configuration.nix
index c6682f8..c7172dc 100644
--- a/modules/flake-parts/nixosConfigurations.sbd-0.main.infra.holo.host/configuration.nix
+++ b/modules/flake-parts/nixosConfigurations.sbd-0.main.infra.holo.host/configuration.nix
@@ -35,9 +35,9 @@
     primaryIpv4 = "65.108.241.120";
   };
 
-  networking.hostName = {
+  networking = {
     inherit (config.passthru) hostName domain;
-  }; # Define your hostname.
+  };
   hostName = "${config.passthru.primaryIpv4}";
 
   nix.settings.max-jobs = 8;