diff --git a/configuration.nix b/configuration.nix
index 0148767..30e566f 100644
--- a/configuration.nix
+++ b/configuration.nix
@@ -112,6 +112,7 @@
   ];
 
   networking = {
+    domain = "hyp";
     firewall.enable = false;
     useDHCP = false;
 
diff --git a/flake.nix b/flake.nix
index ce3af39..8385b32 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,15 +26,20 @@
       machines = import ./machines;
       # TODO: Maybe use mergeAttrLists
       mkNixosSystems = systemDef:
-        nixpkgs.lib.foldlAttrs (acc: name: machine:
-          acc // {
-            "${name}" = nixpkgs.lib.nixosSystem (systemDef machine);
-          }) { } machines;
+        nixpkgs.lib.foldlAttrs
+          (acc: name: machine:
+            acc // {
+              "${name}" = nixpkgs.lib.nixosSystem (systemDef machine);
+            })
+          { }
+          machines;
       mkDeployNodes = nodeDef:
         nixpkgs.lib.foldlAttrs
-        (acc: name: machine: acc // { "${name}" = nodeDef machine; }) { }
-        machines;
-    in {
+          (acc: name: machine: acc // { "${name}" = nodeDef machine; })
+          { }
+          machines;
+    in
+    {
       devShells.${system}.default = pkgs.mkShell {
         packages = [
           pkgs.libsecret
@@ -76,6 +81,7 @@
       };
 
       checks = builtins.mapAttrs
-        (system: deployLib: deployLib.deployChecks self.deploy) deploy-rs.lib;
+        (system: deployLib: deployLib.deployChecks self.deploy)
+        deploy-rs.lib;
     };
 }
diff --git a/modules/custom/k3s.nix b/modules/custom/k3s.nix
index 0d5ae49..f851be6 100644
--- a/modules/custom/k3s.nix
+++ b/modules/custom/k3s.nix
@@ -17,10 +17,10 @@ in {
     environment.systemPackages = [ pkgs.k3s ];
     services.k3s.enable = true;
     services.k3s.role = "server";
-    # Temporary fix: by default the full hostname of the server (jefke.hyp) is not included into the Subject Alternative Name of certificates of the server.
-    # We can hardcode this as a CLI flag to k3s.
-    services.k3s.extraFlags = "--tls-san jefke.hyp --data-dir /mnt/data/k3s";
+    # TODO: parameterize data disk mount point.
+    services.k3s.extraFlags = "--tls-san ${config.networking.fqdn} --data-dir /mnt/data/k3s";
 
+    # TODO: parameterize data disk mount point.
     # TODO: use kubenix for this.
     system.activationScripts.k3s-bootstrap.text =
       let