diff --git a/flake.lock b/flake.lock
index 9b2508b..e648170 100644
--- a/flake.lock
+++ b/flake.lock
@@ -42,11 +42,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1771204072,
-        "narHash": "sha256-s27Es43FfrMfRXXSll0PM9zRvSer6dDtNZ5WpsIlcyY=",
+        "lastModified": 1771875971,
+        "narHash": "sha256-D3PN4o8RtyHEjlAtsLa6M9xRjIwtMUk4pIkfsNSMAvQ=",
         "owner": "lenianiva",
         "repo": "lean4-nix",
-        "rev": "de6f06ae44260581d953d485219dcd2bf86aa685",
+        "rev": "faebfa2e0d7093fea3ffaa493b316bf3449c1dbf",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index a947657..3ea0dea 100644
--- a/flake.nix
+++ b/flake.nix
@@ -27,19 +27,19 @@
         self',
         config,
         ...
-      }: let lake2nix = pkgs.callPackage lean4-nix.lake {};
-        in {
+      }: let
+        lake2nix = pkgs.callPackage lean4-nix.lake {};
+      in {
         _module.args.pkgs = import nixpkgs {
           inherit system;
           overlays = [(lean4-nix.readToolchainFile ./lean-toolchain)];
         };
 
         # Build the library with `nix build`
-        packages.default =
-          lake2nix.mkPackage {
-            name = "LSpec";
-            src = ./.;
-          };
+        packages.default = lake2nix.mkPackage {
+          name = "LSpec";
+          src = ./.;
+        };
 
         devShells.default = pkgs.mkShell {
           packages = with pkgs.lean; [lean-all];
diff --git a/lean-toolchain b/lean-toolchain
index 5249182..4c685fa 100644
--- a/lean-toolchain
+++ b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:v4.27.0
+leanprover/lean4:v4.28.0