diff --git a/nix/nixos-module/defaults.nix b/nix/nixos-module/defaults.nix
index bea0fba..47dbe61 100644
--- a/nix/nixos-module/defaults.nix
+++ b/nix/nixos-module/defaults.nix
@@ -13,4 +13,6 @@
   networking.hostName = hostName;
 
   users.users.root.initialHashedPassword = "";
+
+  system.stateVersion = "20.09";
 }