diff --git a/flake.nix b/flake.nix
index bc32b3e..8c137c1 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,7 +1,7 @@
 {
   description = "An Invoice Ninja package and module.";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-26.05";
 
   outputs =
     { self, nixpkgs, nix, }:
diff --git a/tests/default.nix b/tests/default.nix
index 1274983..cbae60b 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -6,8 +6,6 @@
     ../nixos-module/invoiceninja.nix
   ];
 
-  system.stateVersion = "25.11";
-
   nixpkgs.config.allowUnfree = true;
 
   users.users.test = {