why do i have to repeat so much here?

I'm learning my way around the module system, and trying to write a small
Environment module that creates a record based on a given type. My code
works, but it looks like i had to essentially write out the record
definition thrice. Is there a better way to do this?

Here's the definition of the module

/--------------------------------
$ cat environment.mli

module type ENV = sig
  type dict

  type env = {
    dict : dict;
    op : Types.uop
  }
end

module Make (Dict : sig type t end) : ENV with type dict = Dict.t

$ cat environment.ml

module type ENV = sig
  type dict

  type env = {
    dict : dict;
    op : Types.uop
  }
end

module Make (Dict : sig type t end) = struct
  type dict = Dict.t

  type env = {
    dict : dict;
    op : Types.uop
  }
end

\--------------------------------

and I'm using it in the following code:

/--------------------------------
module Evaluator =
  functor (Env : ENV) ->
  functor (E : ENGINE with type dict = Env.dict) ->
  struct ... end

module Env = Environment.Make (Trie)

module Eval = Evaluator.Evaluator (Env) (TrieEngine)
\--------------------------------

martin