diff --git a/modules/nixos/server/binary-cache/default.nix b/modules/nixos/server/binary-cache/default.nix
index b906660..c96abe7 100644
--- a/modules/nixos/server/binary-cache/default.nix
+++ b/modules/nixos/server/binary-cache/default.nix
@@ -10,7 +10,7 @@ in
       users = {
         groups.nix-serve = {};
         users.nix-serve = {
-          group = nix-serve;
+          group = "nix-serve";
           isSystemUser = true;
         };
       };