diff --git a/flake.lock b/flake.lock
index 421037e..53fe38d 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,23 +1,5 @@
 {
   "nodes": {
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1731533236,
-        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1733935885,
@@ -36,22 +18,22 @@
     },
     "root": {
       "inputs": {
-        "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "systems": "systems"
       }
     },
     "systems": {
       "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "lastModified": 1689347949,
+        "narHash": "sha256-12tWmuL2zgBgZkdoB6qXZsgJEH9LR3oUgpaQq2RbI80=",
         "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "repo": "default-linux",
+        "rev": "31732fcf5e8fea42e59c2488ad31a0e651500f68",
         "type": "github"
       },
       "original": {
         "owner": "nix-systems",
-        "repo": "default",
+        "repo": "default-linux",
         "type": "github"
       }
     }
diff --git a/flake.nix b/flake.nix
index 3a8d591..522c76a 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,59 +1,45 @@
 {
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
-    flake-utils.url = "github:numtide/flake-utils";
-  };
-
-  nixConfig = {
-    extra-substituters = "https://anmonteiro.nix-cache.workers.dev";
-    extra-trusted-public-keys = "ocaml.nix-cache.com-1:/xI2h2+56rwFfKyyFVbkJSeGqSIYMC/Je+7XXqGKDIY=";
+    systems.url = "github:nix-systems/default-linux";
   };
 
   outputs =
     {
       self,
       nixpkgs,
-      flake-utils,
+      systems,
     }:
     let
+      forAllSystems =
+        function: nixpkgs.lib.genAttrs (import systems) (system: function nixpkgs.legacyPackages.${system});
       version = builtins.toString self.lastModified;
-    in
-    flake-utils.lib.eachDefaultSystem (
-      system:
-      let
-        pkgs = import nixpkgs {
-          inherit system;
+      getPkgs = builtins.attrValues;
+      deps = pkgs: {
+        minimal = getPkgs {
+          inherit (pkgs.ocamlPackages)
+            dune_3
+            ocaml
+            angstrom
+            angstrom-unix
+            ppx_inline_test
+            ;
         };
-        inherit (pkgs) mkShell ocamlPackages;
-        inherit (ocamlPackages)
-          dune_3
-          ocaml
-          utop
-          ocaml-lsp
-          ocamlformat
-          ocamlformat-rpc-lib
-          angstrom
-          angstrom-unix
-          ppx_inline_test
-          ;
-        minimal = [
-          dune_3
-          ocaml
-          angstrom
-          angstrom-unix
-          ppx_inline_test
-        ];
-        dev = [
-          utop
-          ocaml-lsp
-          ocamlformat
-          ocamlformat-rpc-lib
-          pkgs.just
-        ];
-      in
-      {
-        devShells.default = mkShell {
-          buildInputs = minimal ++ dev;
+        dev = getPkgs {
+          inherit (pkgs.ocamlPackages)
+            utop
+            ocaml-lsp
+            ocamlformat
+            ocamlformat-rpc-lib
+            ;
+          inherit (pkgs) just;
+        };
+      };
+    in
+    {
+      devShells = forAllSystems (pkgs: {
+        default = pkgs.mkShell {
+          packages = with (deps pkgs); minimal ++ dev;
           shellHook =
             let
               justFile = ''
@@ -82,59 +68,46 @@
               printf '${justFile}' > justfile
             '';
         };
+      });
 
-        checks.default = pkgs.callPackage ./nix/test.nix {
-          culr = self.packages.${system}.tests;
+      checks = forAllSystems (pkgs: {
+        default = pkgs.callPackage ./nix/test.nix {
+          culr = self.packages.${pkgs.system}.tests;
           inherit version;
         };
+      });
 
-        packages.default = pkgs.callPackage ./nix/default.nix {
-          ocaml-deps = minimal;
-          inherit version;
-        };
-
-        packages.debug = pkgs.callPackage ./nix/default.nix {
-          debug = true;
-          ocaml-deps = minimal;
-          inherit version;
-        };
-
-        packages.tests = pkgs.callPackage ./nix/default.nix {
-          debug = true;
-          ocaml-deps = minimal;
-          doCheck = true;
-          inherit version;
-        };
-      }
-    )
-    // {
-      nixosModules.culr = import ./nix/module.nix { overlays = [ self.overlays.culr ]; };
-
-      overlays.culr =
-        final: prev:
+      packages = forAllSystems (
+        pkgs:
         let
-          ocaml-deps =
-            let
-              inherit (prev.ocamlPackages)
-                dune_3
-                ocaml
-                angstrom
-                angstrom-unix
-                ppx_inline_test
-                ;
-            in
-            [
-              dune_3
-              ocaml
-              angstrom
-              angstrom-unix
-              ppx_inline_test
-            ];
+          minimal = (deps pkgs).minimal;
         in
         {
-          culr = final.callPackage ./nix/default.nix {
-            inherit ocaml-deps version;
+          culr = self.packages.${pkgs.system}.default;
+          default = pkgs.ocamlPackages.callPackage ./nix/default.nix {
+            ocaml-deps = minimal;
+            inherit version;
           };
+          debug = pkgs.ocamlPackages.callPackage ./nix/default.nix {
+            debug = true;
+            ocaml-deps = minimal;
+            inherit version;
+          };
+          tests = pkgs.ocamlPackages.callPackage ./nix/default.nix {
+            debug = true;
+            ocaml-deps = minimal;
+            doCheck = true;
+            inherit version;
+          };
+        }
+      );
+
+      nixosModules.culr =
+        { pkgs, ... }:
+        {
+          imports = [ ./nix/module.nix ];
+          programs.culr.package = self.packages.${pkgs.system}.culr;
         };
+
     };
 }
diff --git a/nix/culr-module.nix b/nix/culr-module.nix
deleted file mode 100644
index a60f6a2..0000000
--- a/nix/culr-module.nix
+++ /dev/null
@@ -1,51 +0,0 @@
-{
-  pkgs,
-  lib,
-  config,
-  ...
-}: let
-  inherit (lib) mkIf mkEnableOption mkOption types concatStringsSep typeOf;
-  cfg = config.programs.culr;
-in {
-  options.programs.culr = {
-    enable = mkEnableOption "culr";
-    pattern = mkOption {
-      type = with types; either str (listOf int);
-      default = [];
-      description = "colourising pattern";
-    };
-    palette = mkOption {
-      type = with types; listOf str;
-      default = [];
-      description = "palette to use in comma separated RGB hex eg. #0f0f0f";
-    };
-    separators = mkOption {
-      type = with types; str;
-      default = "";
-      description = "char list of separators to use";
-    };
-    delimiters = mkOption {
-      type = with types; str;
-      default = "";
-      description = "char list of delimiters to use";
-    };
-  };
-
-  config = mkIf cfg.enable {
-    environment.systemPackages = let inherit (pkgs) culr; in [culr];
-    environment.sessionVariables = {
-      CULR_ORDER = let
-        serialise = {
-          list = list: concatStringsSep ";" (map (i: builtins.toString i) list);
-          string = s: s;
-        };
-      in
-        mkIf (cfg.pattern != "" && cfg.pattern != [])
-        (serialise.${typeOf cfg.pattern}
-          cfg.pattern);
-      CULR_PALETTE = mkIf (cfg.palette != []) (concatStringsSep ";" cfg.palette);
-      CULR_SEP = mkIf (cfg.separators != "") (cfg.separators);
-      CULR_DELIM = mkIf (cfg.delimiters != "") (cfg.delimiters);
-    };
-  };
-}
diff --git a/nix/default.nix b/nix/default.nix
index 522cc4c..2e4f9c7 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -2,34 +2,35 @@
   pkgs,
   lib,
   ocaml-deps,
-  ocamlPackages,
+  buildDunePackage,
   version,
   debug ? false,
   doCheck ? false,
   ...
 }:
-ocamlPackages.buildDunePackage {
+buildDunePackage {
   pname = "culr";
   version = "0.1-vivid-${version}";
 
   minimalOCamlVersion = "5.2";
 
   src = ./..;
-  nativeBuildInputs = [pkgs.git];
+  nativeBuildInputs = [ pkgs.git ];
   buildInputs = ocaml-deps;
 
   buildPhase =
-    if debug
-    then ''
-      runHook preBuild
-      dune build -p culr --profile debug ''${enableParallelBuilding:+-j $NIX_BUILD_CORES}
-      runHook postBuild
-    ''
-    else ''
-      runHook preBuild
-      dune build -p culr --profile release  ''${enableParallelBuilding:+-j $NIX_BUILD_CORES}
-      runHook postBuild
-    '';
+    if debug then
+      ''
+        runHook preBuild
+        dune build -p culr --profile debug ''${enableParallelBuilding:+-j $NIX_BUILD_CORES}
+        runHook postBuild
+      ''
+    else
+      ''
+        runHook preBuild
+        dune build -p culr --profile release  ''${enableParallelBuilding:+-j $NIX_BUILD_CORES}
+        runHook postBuild
+      '';
 
   checkPhase = ''
     dune runtest
diff --git a/nix/module.nix b/nix/module.nix
index 90e3b76..d8db058 100644
--- a/nix/module.nix
+++ b/nix/module.nix
@@ -1,4 +1,60 @@
-{overlays}: {
-  nixpkgs.overlays = overlays;
-  imports = [./culr-module.nix];
+{
+  lib,
+  config,
+  ...
+}:
+let
+  inherit (lib)
+    mkIf
+    mkEnableOption
+    mkPackageOption
+    mkOption
+    types
+    concatStringsSep
+    typeOf
+    ;
+  cfg = config.programs.culr;
+in
+{
+  options.programs.culr = {
+    enable = mkEnableOption "culr";
+    package = mkPackageOption { } "" { };
+    pattern = mkOption {
+      type = with types; either str (listOf int);
+      default = [ ];
+      description = "colourising pattern";
+    };
+    palette = mkOption {
+      type = with types; listOf str;
+      default = [ ];
+      description = "palette to use in comma separated RGB hex eg. #0f0f0f";
+    };
+    separators = mkOption {
+      type = with types; str;
+      default = "";
+      description = "char list of separators to use";
+    };
+    delimiters = mkOption {
+      type = with types; str;
+      default = "";
+      description = "char list of delimiters to use";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [ cfg.package ];
+    environment.sessionVariables = {
+      CULR_ORDER =
+        let
+          serialise = {
+            list = list: concatStringsSep ";" (map (i: builtins.toString i) list);
+            string = s: s;
+          };
+        in
+        mkIf (cfg.pattern != "" && cfg.pattern != [ ]) (serialise.${typeOf cfg.pattern} cfg.pattern);
+      CULR_PALETTE = mkIf (cfg.palette != [ ]) (concatStringsSep ";" cfg.palette);
+      CULR_SEP = mkIf (cfg.separators != "") (cfg.separators);
+      CULR_DELIM = mkIf (cfg.delimiters != "") (cfg.delimiters);
+    };
+  };
 }