diff --git a/hosts/brzeczyszczykiewicz/configuration.nix b/hosts/brzeczyszczykiewicz/configuration.nix
index 43c1f9f..4c637b1 100644
--- a/hosts/brzeczyszczykiewicz/configuration.nix
+++ b/hosts/brzeczyszczykiewicz/configuration.nix
@@ -17,5 +17,5 @@
 
   # Don't change (even during upgrades) unless you know what you are doing.
   # See https://search.nixos.org/options?show=system.stateVersion
-  system.stateVersion = "23.05";
+  system.stateVersion = "25.11";
 }
diff --git a/hosts/georg/configuration.nix b/hosts/georg/configuration.nix
index 405f900..05082d4 100644
--- a/hosts/georg/configuration.nix
+++ b/hosts/georg/configuration.nix
@@ -32,5 +32,5 @@
 
   # Don't change (even during upgrades) unless you know what you are doing.
   # See https://search.nixos.org/options?show=system.stateVersion
-  system.stateVersion = "23.05";
+  system.stateVersion = "25.11";
 }
diff --git a/hosts/shark/configuration.nix b/hosts/shark/configuration.nix
index 5036782..c53a220 100644
--- a/hosts/shark/configuration.nix
+++ b/hosts/shark/configuration.nix
@@ -15,5 +15,5 @@
 
   # Don't change (even during upgrades) unless you know what you are doing.
   # See https://search.nixos.org/options?show=system.stateVersion
-  system.stateVersion = "23.05";
+  system.stateVersion = "25.11";
 }
diff --git a/hosts/skrott/configuration.nix b/hosts/skrott/configuration.nix
index e1d5fe1..a4d9869 100644
--- a/hosts/skrott/configuration.nix
+++ b/hosts/skrott/configuration.nix
@@ -96,11 +96,11 @@
   };
 
   # https://github.com/NixOS/nixpkgs/issues/84105
-  boot.kernelParams = [
+  boot.kernelParams = lib.mkIf (!config.virtualisation.isVmVariant) [
     "console=ttyUSB0,9600"
     # "console=tty1" # Already part of the module
   ];
-  systemd.services."serial-getty@ttyUSB0" = {
+  systemd.services."serial-getty@ttyUSB0" = lib.mkIf (!config.virtualisation.isVmVariant) {
     enable = true;
     wantedBy = [ "getty.target" ]; # to start at boot
     serviceConfig.Restart = "always"; # restart when session is closed