diff --git a/flake.nix b/flake.nix
index f77af51..59d22b4 100644
--- a/flake.nix
+++ b/flake.nix
@@ -124,12 +124,12 @@
       "${pname}" = package;
       default = package;
     };
-    nixosModules.default = { lib, config, ... }:
+    nixosModules.default = { lib, config, pkgs, ... }:
       with lib;
       let
         cfg = config.services.actual;
         dataDir = "/var/lib/actual";
-        cfgFile = writeText "actual.json" (builtins.toJSON {
+        cfgFile = pkgs.writeText "actual.json" (builtins.toJSON {
           inherit dataDir;
           inherit (cfg) hostname port;
           serverFiles = "${dataDir}/server-files";