diff --git a/default.nix b/default.nix
index ed9c1ae28..e688de58e 100644
--- a/default.nix
+++ b/default.nix
@@ -1,21 +1,38 @@
-{ pkgs ? import ./nix/default.nix {}
+{ stdenv
+, naersk
+, libiconv
+, pkgconfig
 }:
-
-with pkgs;
-
 let
-
-  self = {
-    inherit (tokenizersPackages)
-      tokenizers
-      tokenizers-haskell
-      ;
-    
-    shell = import ./shell.nix {
-      inherit pkgs;
-    };
+  patchLibs =
+    if stdenv.isDarwin
+    then ''
+      install_name_tool -id $out/lib/libtokenizers_haskell.dylib $out/lib/libtokenizers_haskell.dylib
+    ''
+    else ''
+      patchelf --set-rpath "${stdenv.cc.cc.lib}/lib:$out/lib" $out/lib/libtokenizers_haskell.so
+    '';
+in {
+  tokenizers = naersk.buildPackage {
+    src = ./.;
+    buildInputs = [ libiconv pkgconfig ];
+    release = true;
+    cargoBuildOptions = x: x ++ [ "-p" "tokenizers" ];
+    cargoTestOptions = x: x ++ [ "-p" "tokenzers" ];
+    copyBins = true;
+    copyLibs = true;
+    copyTarget = false;
   };
 
-in
-
-  self
+  tokenizers-haskell = naersk.buildPackage {
+    src = ./.;
+    buildInputs = [ libiconv pkgconfig ];
+    release = true;
+    cargoBuildOptions = x: x ++ [ "-p" "tokenizers-haskell" ];
+    cargoTestOptions = x: x ++ [ "-p" "tokenizers-haskell" ];
+    copyBins = false;
+    copyLibs = true;
+    copyTarget = false;
+    overrideMain = x: x // { postInstall = patchLibs; };
+  };
+}
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 000000000..1ccfd3e9f
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,74 @@
+{
+  "nodes": {
+    "naersk": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1629707199,
+        "narHash": "sha256-sGxlmfp5eXL5sAMNqHSb04Zq6gPl+JeltIZ226OYN0w=",
+        "owner": "nix-community",
+        "repo": "naersk",
+        "rev": "df71f5e4babda41cd919a8684b72218e2e809fa9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "naersk",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1630084536,
+        "narHash": "sha256-ZFO/c1n5NNzHdY848Lfrbh8QN8MdP6oajbj4Z55rVXs=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "40f337454d6c76bc12500564f4553d6853e83aeb",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1630084536,
+        "narHash": "sha256-ZFO/c1n5NNzHdY848Lfrbh8QN8MdP6oajbj4Z55rVXs=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "40f337454d6c76bc12500564f4553d6853e83aeb",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "naersk": "naersk",
+        "nixpkgs": "nixpkgs_2",
+        "utils": "utils"
+      }
+    },
+    "utils": {
+      "locked": {
+        "lastModified": 1629481132,
+        "narHash": "sha256-JHgasjPR0/J1J3DRm4KxM4zTyAj4IOJY8vIl75v/kPI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "997f7efcb746a9c140ce1f13c72263189225f482",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 000000000..334c42c06
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,27 @@
+{
+  description = "huggingface tokenizers";
+
+  inputs = {
+    utils.url = "github:numtide/flake-utils";
+    naersk.url = "github:nix-community/naersk";
+  };
+
+  outputs = { self, nixpkgs, utils, naersk, ... }: {
+
+      overlay = final: prev: rec {
+        tokenizersPackages = prev.callPackage ./. { naersk = naersk.lib."${final.system}"; };
+        tokenizers-haskell = tokenizersPackages.tokenizers-haskell;
+        tokenizers_haskell = tokenizersPackages.tokenizers-haskell; # for backwards-compatibility
+      };
+
+    } // (utils.lib.eachSystem ["x86_64-darwin" "x86_64-linux"] (system:
+      let
+        pkgs = import nixpkgs { inherit system; overlays = [ naersk.overlay ]; };
+      in {
+        packages = pkgs.callPackage ./. {};
+        devShell = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [ cargo rustc rls libiconv pkgconfig ];
+        };
+      }
+    ));
+}
diff --git a/nix/default.nix b/nix/default.nix
deleted file mode 100644
index 9dd0179f4..000000000
--- a/nix/default.nix
+++ /dev/null
@@ -1,19 +0,0 @@
-{}:
-
-let
-
-  sources = import ./sources.nix { inherit pkgs; };
-  nixpkgsSrc = sources.nixpkgs-unstable;
-
-  overlays =
-    [ (pkgs: _: with pkgs; {
-        naersk = callPackage sources.naersk {};
-      })
-      (import ./pkgs.nix)
-    ];
-
-  pkgs = import nixpkgsSrc {
-    inherit overlays;
-  };
-  
-in pkgs
diff --git a/nix/pkgs.nix b/nix/pkgs.nix
deleted file mode 100644
index a88283c69..000000000
--- a/nix/pkgs.nix
+++ /dev/null
@@ -1,8 +0,0 @@
-pkgs: _: with pkgs; {
-  tokenizersPackages = import ./rust.nix {
-    inherit
-      stdenv
-      pkgs
-      ;
-  };
-}
diff --git a/nix/rust.nix b/nix/rust.nix
deleted file mode 100644
index bcd66b8b2..000000000
--- a/nix/rust.nix
+++ /dev/null
@@ -1,45 +0,0 @@
-{ stdenv
-, pkgs
-}:
-
-with pkgs;
-
-let
-
-  patchLibs =
-    if stdenv.isDarwin
-    then ''
-      install_name_tool -id $out/lib/libtokenizers_haskell.dylib $out/lib/libtokenizers_haskell.dylib
-    ''
-    else ''
-      patchelf --set-rpath "${stdenv.cc.cc.lib}/lib:$out/lib" $out/lib/libtokenizers_haskell.so
-    '';
-
-  self = {
-    tokenizers = naersk.buildPackage {
-      src = ../.;
-      buildInputs = [ libiconv pkgconfig ];
-      release = true;
-      cargoBuildOptions = x: x ++ [ "-p" "tokenizers" ];
-      cargoTestOptions = x: x ++ [ "-p" "tokenzers" ];
-      copyBins = true;
-      copyLibs = true;
-      copyTarget = false;
-    };
-
-    tokenizers-haskell = naersk.buildPackage {
-      src = ../.;
-      buildInputs = [ libiconv pkgconfig ];
-      release = true;
-      cargoBuildOptions = x: x ++ [ "-p" "tokenizers-haskell" ];
-      cargoTestOptions = x: x ++ [ "-p" "tokenizers-haskell" ];
-      copyBins = false;
-      copyLibs = true;
-      copyTarget = false;
-      overrideMain = x: x // { postInstall = patchLibs; };
-    };
-  };
-
-in
-
-  self
diff --git a/nix/sources.json b/nix/sources.json
deleted file mode 100644
index a908cbc6d..000000000
--- a/nix/sources.json
+++ /dev/null
@@ -1,38 +0,0 @@
-{
-    "naersk": {
-        "branch": "master",
-        "description": "Build rust crates in Nix. No configuration, no code generation, no IFD. Sandbox friendly.",
-        "homepage": "",
-        "owner": "nmattia",
-        "repo": "naersk",
-        "rev": "b3b099d669fc8b18d361c249091c9fe95d57ebbb",
-        "sha256": "156fbnr5s2n1xxbbk2z9xa7c5g2z5fdpqmjjs6n9ipbr038n0z3s",
-        "type": "tarball",
-        "url": "https://github.com/nmattia/naersk/archive/b3b099d669fc8b18d361c249091c9fe95d57ebbb.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "niv": {
-        "branch": "master",
-        "description": "Easy dependency management for Nix projects",
-        "homepage": "https://github.com/nmattia/niv",
-        "owner": "nmattia",
-        "repo": "niv",
-        "rev": "af958e8057f345ee1aca714c1247ef3ba1c15f5e",
-        "sha256": "1qjavxabbrsh73yck5dcq8jggvh3r2jkbr6b5nlz5d9yrqm9255n",
-        "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/af958e8057f345ee1aca714c1247ef3ba1c15f5e.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixpkgs-unstable": {
-        "branch": "nixpkgs-unstable",
-        "description": "Nix Packages collection",
-        "homepage": "",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "410bbd828cdc6156aecd5bc91772ad3a6b1099c7",
-        "sha256": "0idvgvpgnzvk03yvd77lrca9qib936fq2x690jvk5gk3blsckz3r",
-        "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/410bbd828cdc6156aecd5bc91772ad3a6b1099c7.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    }
-}
diff --git a/nix/sources.nix b/nix/sources.nix
deleted file mode 100644
index 1938409dd..000000000
--- a/nix/sources.nix
+++ /dev/null
@@ -1,174 +0,0 @@
-# This file has been generated by Niv.
-
-let
-
-  #
-  # The fetchers. fetch_<type> fetches specs of type <type>.
-  #
-
-  fetch_file = pkgs: name: spec:
-    let
-      name' = sanitizeName name + "-src";
-    in
-      if spec.builtin or true then
-        builtins_fetchurl { inherit (spec) url sha256; name = name'; }
-      else
-        pkgs.fetchurl { inherit (spec) url sha256; name = name'; };
-
-  fetch_tarball = pkgs: name: spec:
-    let
-      name' = sanitizeName name + "-src";
-    in
-      if spec.builtin or true then
-        builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
-      else
-        pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
-
-  fetch_git = name: spec:
-    let
-      ref =
-        if spec ? ref then spec.ref else
-          if spec ? branch then "refs/heads/${spec.branch}" else
-            if spec ? tag then "refs/tags/${spec.tag}" else
-              abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
-    in
-      builtins.fetchGit { url = spec.repo; inherit (spec) rev; inherit ref; };
-
-  fetch_local = spec: spec.path;
-
-  fetch_builtin-tarball = name: throw
-    ''[${name}] The niv type "builtin-tarball" is deprecated. You should instead use `builtin = true`.
-        $ niv modify ${name} -a type=tarball -a builtin=true'';
-
-  fetch_builtin-url = name: throw
-    ''[${name}] The niv type "builtin-url" will soon be deprecated. You should instead use `builtin = true`.
-        $ niv modify ${name} -a type=file -a builtin=true'';
-
-  #
-  # Various helpers
-  #
-
-  # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695
-  sanitizeName = name:
-    (
-      concatMapStrings (s: if builtins.isList s then "-" else s)
-        (
-          builtins.split "[^[:alnum:]+._?=-]+"
-            ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)
-        )
-    );
-
-  # The set of packages used when specs are fetched using non-builtins.
-  mkPkgs = sources: system:
-    let
-      sourcesNixpkgs =
-        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { inherit system; };
-      hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
-      hasThisAsNixpkgsPath = <nixpkgs> == ./.;
-    in
-      if builtins.hasAttr "nixpkgs" sources
-      then sourcesNixpkgs
-      else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then
-        import <nixpkgs> {}
-      else
-        abort
-          ''
-            Please specify either <nixpkgs> (through -I or NIX_PATH=nixpkgs=...) or
-            add a package called "nixpkgs" to your sources.json.
-          '';
-
-  # The actual fetching function.
-  fetch = pkgs: name: spec:
-
-    if ! builtins.hasAttr "type" spec then
-      abort "ERROR: niv spec ${name} does not have a 'type' attribute"
-    else if spec.type == "file" then fetch_file pkgs name spec
-    else if spec.type == "tarball" then fetch_tarball pkgs name spec
-    else if spec.type == "git" then fetch_git name spec
-    else if spec.type == "local" then fetch_local spec
-    else if spec.type == "builtin-tarball" then fetch_builtin-tarball name
-    else if spec.type == "builtin-url" then fetch_builtin-url name
-    else
-      abort "ERROR: niv spec ${name} has unknown type ${builtins.toJSON spec.type}";
-
-  # If the environment variable NIV_OVERRIDE_${name} is set, then use
-  # the path directly as opposed to the fetched source.
-  replace = name: drv:
-    let
-      saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
-      ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
-    in
-      if ersatz == "" then drv else
-        # this turns the string into an actual Nix path (for both absolute and
-        # relative paths)
-        if builtins.substring 0 1 ersatz == "/" then /. + ersatz else /. + builtins.getEnv "PWD" + "/${ersatz}";
-
-  # Ports of functions for older nix versions
-
-  # a Nix version of mapAttrs if the built-in doesn't exist
-  mapAttrs = builtins.mapAttrs or (
-    f: set: with builtins;
-    listToAttrs (map (attr: { name = attr; value = f attr set.${attr}; }) (attrNames set))
-  );
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
-  range = first: last: if first > last then [] else builtins.genList (n: first + n) (last - first + 1);
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
-  stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
-  stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
-  concatMapStrings = f: list: concatStrings (map f list);
-  concatStrings = builtins.concatStringsSep "";
-
-  # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
-  optionalAttrs = cond: as: if cond then as else {};
-
-  # fetchTarball version that is compatible between all the versions of Nix
-  builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
-    let
-      inherit (builtins) lessThan nixVersion fetchTarball;
-    in
-      if lessThan nixVersion "1.12" then
-        fetchTarball ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-      else
-        fetchTarball attrs;
-
-  # fetchurl version that is compatible between all the versions of Nix
-  builtins_fetchurl = { url, name ? null, sha256 }@attrs:
-    let
-      inherit (builtins) lessThan nixVersion fetchurl;
-    in
-      if lessThan nixVersion "1.12" then
-        fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-      else
-        fetchurl attrs;
-
-  # Create the final "sources" from the config
-  mkSources = config:
-    mapAttrs (
-      name: spec:
-        if builtins.hasAttr "outPath" spec
-        then abort
-          "The values in sources.json should not have an 'outPath' attribute"
-        else
-          spec // { outPath = replace name (fetch config.pkgs name spec); }
-    ) config.sources;
-
-  # The "config" used by the fetchers
-  mkConfig =
-    { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
-    , sources ? if isNull sourcesFile then {} else builtins.fromJSON (builtins.readFile sourcesFile)
-    , system ? builtins.currentSystem
-    , pkgs ? mkPkgs sources system
-    }: rec {
-      # The sources, i.e. the attribute set of spec name to spec
-      inherit sources;
-
-      # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers
-      inherit pkgs;
-    };
-
-in
-mkSources (mkConfig {}) // { __functor = _: settings: mkSources (mkConfig settings); }
diff --git a/shell.nix b/shell.nix
deleted file mode 100644
index 6ac64a392..000000000
--- a/shell.nix
+++ /dev/null
@@ -1,14 +0,0 @@
-{ pkgs ? import ./nix/default.nix {}
-}:
-
-with pkgs;
-
-let
-
-  shell = mkShell {
-    nativeBuildInputs = [ cargo rustc rls libiconv pkgconfig ];
-  };
-
-in
-
-  shell