diff --git a/flake.lock b/flake.lock
index 944b3a2..188d193 100644
--- a/flake.lock
+++ b/flake.lock
@@ -17,16 +17,18 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1630572390,
-        "narHash": "sha256-xPqD/SFQ/QKxR85ZQ/WkNEAI6yfCW0XFXmmWBp2KKLw=",
-        "owner": "NixOS",
+        "lastModified": 1630679442,
+        "narHash": "sha256-wPCqej7mCmt8g4OXDQE/SCyhNF72GS9ws5pzmCiM/C0=",
+        "owner": "ehmry",
         "repo": "nixpkgs",
-        "rev": "f6645fdf90d443c38fbc98125a4665f5e798e807",
+        "rev": "8fbf6c0f2a1b973dde6707ab471910312312b225",
         "type": "github"
       },
       "original": {
-        "id": "nixpkgs",
-        "type": "indirect"
+        "owner": "ehmry",
+        "ref": "nimPackages",
+        "repo": "nixpkgs",
+        "type": "github"
       }
     },
     "nixpkgs_2": {
diff --git a/flake.nix b/flake.nix
index ce84969..43b1fb4 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,6 +1,7 @@
 {
   description = "Syndicate utilities";
 
+  inputs.nixpkgs.url = "github:ehmry/nixpkgs/nimPackages";
   inputs.rust.url = "github:oxalica/rust-overlay";
 
   outputs = { self, nixpkgs, rust }:
@@ -14,13 +15,15 @@
         let rust' = (prev.extend rust.overlay).rust-bin.nightly.latest.default;
         in {
           lib = prev.lib.extend libOverlay;
-          preserves-tools = final.callPackage ./preserves-tools { rust = rust'; };
+          preserves-nim = final.callPackage ./preserves-nim { };
+          preserves-tools =
+            final.callPackage ./preserves-tools { rust = rust'; };
           syndicate-rs = final.callPackage ./syndicate-rs { rust = rust'; };
         };
 
       packages = forEachSystem (system:
         let pkgs = nixpkgs.legacyPackages.${system}.extend self.overlay;
-        in with pkgs; { inherit preserves-tools syndicate-rs; });
+        in with pkgs; { inherit preserves-nim preserves-tools syndicate-rs; });
 
       nixosModules.syndicate-server =
         # A little hack to apply our overlay to this module only.
diff --git a/preserves-nim/default.nix b/preserves-nim/default.nix
new file mode 100644
index 0000000..8715a7e
--- /dev/null
+++ b/preserves-nim/default.nix
@@ -0,0 +1,33 @@
+{ lib, nimPackages, fetchgit }:
+with nimPackages;
+
+let
+  bigints = fetchNimble {
+    pname = "bigints";
+    version = "0.5.0";
+    hash = "sha256-zMTXXC0lYVzXaKl8eC/SA/CymRgovgzxBdvEn1VE9p0=";
+  };
+
+  compiler = fetchNimble {
+    pname = "compiler";
+    version = "1.4.8";
+    hash = "sha256-OaSe9Bn/+rjVk4pJKjjwI9rpnDm/T7lRmKeh/DOPn38=";
+  };
+
+  npeg = fetchNimble {
+    pname = "npeg";
+    version = "0.24.1";
+    hash = "sha256-AKYDrR38345CQxV7kLvglGmkc/m8EX6TGtaFckJL3Dc=";
+  };
+
+in buildNimPackage rec {
+  outputs = [ "out" "dev" ];
+  pname = "preserves";
+  version = "1.0.0";
+  src = fetchgit {
+    url = "https://git.sr.ht/~ehmry/preserves-nim";
+    rev = "v${version}";
+    sha256 = "18702q7vmyf5kkgn9nqf96kcar5pqxisf03ybrqw3hfp95vxixn4";
+  };
+  buildInputs = [ compiler bigints npeg ];
+}