diff --git a/modules/nixos/server/binary-cache/default.nix b/modules/nixos/server/binary-cache/default.nix
index fcf4bd3..b906660 100644
--- a/modules/nixos/server/binary-cache/default.nix
+++ b/modules/nixos/server/binary-cache/default.nix
@@ -7,6 +7,13 @@
 in
   with lib; {
     config = mkIf cfg.enable {
+      users = {
+        groups.nix-serve = {};
+        users.nix-serve = {
+          group = nix-serve;
+          isSystemUser = true;
+        };
+      };
       services = {
         nix-serve = {
           secretKeyFile = "/var/cache-priv-key.pem";