diff --git a/flake.lock b/flake.lock
index 123be4c..7839508 100644
--- a/flake.lock
+++ b/flake.lock
@@ -17,18 +17,16 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1646044487,
-        "narHash": "sha256-2BN9xRr3NeLL9x9X66DiSATzm4nA/G0inc5D0+FtHTA=",
-        "owner": "nixos",
+        "lastModified": 1647199004,
+        "narHash": "sha256-37aHbLhcX6zqeru24AoPPfem6fUQ6are5E38NdbIgJg=",
+        "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "321b67a7448c79a110af2b9eceb0ad4b28f9db8c",
+        "rev": "328bd3c30e4fc4c3d69bc08516f27e8d85f839b6",
         "type": "github"
       },
       "original": {
-        "owner": "nixos",
-        "ref": "release-21.11",
-        "repo": "nixpkgs",
-        "type": "github"
+        "id": "nixpkgs",
+        "type": "indirect"
       }
     },
     "nixpkgs_2": {
@@ -59,11 +57,11 @@
         "nixpkgs": "nixpkgs_2"
       },
       "locked": {
-        "lastModified": 1646014761,
-        "narHash": "sha256-HdXvdU+wV+E1nNzG2vaQsUuBJQID3AB3BX88N8lA37M=",
+        "lastModified": 1647224709,
+        "narHash": "sha256-Lt8Vo2eRahkww3Ia7AyxAiKCf59TW0OWZ9vKd5WvAJ4=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "c7d9566796b3ad5b257e187e1628488c7429b89e",
+        "rev": "fea74aea1b2b99e13338a345034089a344399359",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index cba7082..72ad460 100644
--- a/flake.nix
+++ b/flake.nix
@@ -3,39 +3,48 @@
 
   inputs.rust.url = "github:oxalica/rust-overlay";
 
-  inputs.nixpkgs.url = "github:nixos/nixpkgs/release-21.11";
+  outputs = { self, nixpkgs, rust }: {
+    lib = nixpkgs.lib.extend (import ./lib.nix);
 
-  outputs = { self, nixpkgs, rust }:
-    let
-      forEachSystem = nixpkgs.lib.genAttrs [ "aarch64-linux" "x86_64-linux" ];
-      libOverlay = import ./lib.nix;
-    in {
-      lib = nixpkgs.lib.extend libOverlay;
+    overlays.default = final: prev:
+      let rust' = (prev.extend rust.overlay).rust-bin.nightly.latest.default;
+      in {
+        inherit (self) lib;
 
-      overlay = final: prev:
-        let rust' = (prev.extend rust.overlay).rust-bin.nightly.latest.default;
-        in {
-          lib = prev.lib.extend libOverlay;
-          preserves-nim = final.callPackage ./preserves-nim { };
-          preserves-tools =
-            final.callPackage ./preserves-tools { rust = rust'; };
-          syndicate-server =
-            final.callPackage ./syndicate-server { rust = rust'; };
-        };
-
-      packages = forEachSystem (system:
-        let pkgs = nixpkgs.legacyPackages.${system}.extend self.overlay;
-        in with pkgs; {
-          inherit preserves-nim preserves-tools syndicate-server;
+        nimPackages = prev.nimPackages.overrideScope' (final': prev': {
+          preserves = final'.callPackage ./preserves-nim { };
         });
 
-      nixosModules.syndicate-server =
-        # A little hack to apply our overlay to this module only.
-        let f = import ./nixos/syndicate-server.nix;
-        in { config, lib, pkgs, ... }:
-        f {
-          inherit config lib;
-          pkgs = pkgs.extend self.overlay;
-        };
-    };
+        preserves-tools = final.callPackage ./preserves-tools { rust = rust'; };
+        syndicate-server =
+          final.callPackage ./syndicate-server { rust = rust'; };
+      };
+
+    legacyPackages =
+      self.lib.mapAttrs (system: pkgs: pkgs.extend self.overlays.default) {
+        inherit (nixpkgs.legacyPackages) aarch64-linux x86_64-linux;
+      };
+
+    packages = self.lib.mapAttrs (system: pkgs:
+      with pkgs; {
+        inherit preserves-tools syndicate-server;
+        preserves-nim = nimPackages.preserves;
+      }) self.legacyPackages;
+
+    nixosModules.syndicate-server =
+      # A little hack to apply our overlay to this module only.
+      let f = import ./nixos/syndicate-server.nix;
+      in { config, lib, pkgs, ... }:
+      f {
+        inherit config lib;
+        pkgs = pkgs.extend self.overlays.default;
+      };
+
+    devShells = self.lib.mapAttrs (system: pkgs:
+      with pkgs; {
+        default =
+          mkShell { packages = builtins.attrValues self.packages.${system}; };
+      }) self.legacyPackages;
+
+  };
 }