diff --git a/flake.nix b/flake.nix
index d19ac83..a3b0764 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,6 +26,8 @@
             ocaml-pkgs.ocaml
             ocaml-pkgs.ocamlPackages.utop
             ocaml-pkgs.ocamlPackages.findlib
+            ocaml-pkgs.ocamlPackages.num
+            ocaml-pkgs.ocamlPackages.menhir
             ocaml-pkgs.ocamlPackages.ocamlformat
             ocaml-pkgs.ocamlPackages.ocaml-lsp
           ];