diff --git a/src/context.ml b/src/context.ml
index 29d261d2..b666dbd6 100644
--- a/src/context.ml
+++ b/src/context.ml
@@ -110,9 +110,9 @@ let sexp_of_t t =
       bool (Dynlink_supported.By_the_os.get t.natdynlink_supported)
     ; "supports_shared_libraries",
       bool (Dynlink_supported.By_the_os.get t.supports_shared_libraries)
-    ; "opam_vars", string_hashtbl string t.opam_var_cache
+    ; "opam_vars", Hashtbl.sexp_of_t string string t.opam_var_cache
     ; "ocaml_config", Ocaml_config.sexp_of_t t.ocaml_config
-    ; "which", string_hashtbl (option path) t.which_cache
+    ; "which", Hashtbl.sexp_of_t string (option path) t.which_cache
     ]
 
 let compare a b = compare a.name b.name
diff --git a/src/dsexp/dsexp.ml b/src/dsexp/dsexp.ml
index 83eb5269..635d717d 100644
--- a/src/dsexp/dsexp.ml
+++ b/src/dsexp/dsexp.ml
@@ -5,7 +5,17 @@ module Template = Template
 
 type syntax = Atom.syntax = Jbuild | Dune
 
-include Dsexp0
+type t =
+  | Atom of Atom.t
+  | Quoted_string of string
+  | List of t list
+  | Template of Template.t
+
+let atom_or_quoted_string s =
+  if Atom.is_valid_dune s then
+    Atom (Atom.of_string s)
+  else
+    Quoted_string s
 
 let atom s = Atom (Atom.of_string s)
 
@@ -128,6 +138,7 @@ let prepare_formatter ppf =
     }
 
 module Ast = struct
+  type dsexp = t
   type t =
     | Atom of Loc.t * Atom.t
     | Quoted_string of Loc.t * string
@@ -144,7 +155,7 @@ module Ast = struct
   let loc (Atom (loc, _) | Quoted_string (loc, _) | List (loc, _)
           | Template { loc ; _ }) = loc
 
-  let rec remove_locs t : Dsexp0.t =
+  let rec remove_locs t : dsexp =
     match t with
     | Template t -> Template (Template.remove_locs t)
     | Atom (_, s) -> Atom s
@@ -259,7 +270,6 @@ module To_sexp = struct
   type nonrec 'a t = 'a -> t
   let unit () = List []
   let string = atom_or_quoted_string
-  let atom = string
   let int n = Atom (Atom.of_int n)
   let float f = Atom (Atom.of_float f)
   let bool b = Atom (Atom.of_bool b)
@@ -270,14 +280,8 @@ module To_sexp = struct
   let option f = function
     | None -> List []
     | Some x -> List [f x]
-  let string_set set = list atom (String.Set.to_list set)
-  let string_map f map = list (pair atom f) (String.Map.to_list map)
   let record l =
     List (List.map l ~f:(fun (n, v) -> List [Atom(Atom.of_string n); v]))
-  let string_hashtbl f h =
-    string_map f
-      (Hashtbl.foldi h ~init:String.Map.empty ~f:(fun key data acc ->
-         String.Map.add acc key data))
 
   type field = string * dsexp option
 
@@ -670,21 +674,6 @@ module Of_sexp = struct
        | true -> return None
        | false -> t >>| Option.some)
 
-  let string_set = list string >>| String.Set.of_list
-  let string_map t =
-    list (pair string t) >>= fun bindings ->
-    match String.Map.of_list bindings with
-    | Result.Ok x -> return x
-    | Error (key, _v1, _v2) ->
-      loc >>= fun loc ->
-      of_sexp_errorf loc "key %s present multiple times" key
-
-  let string_hashtbl t =
-    string_map t >>| fun map ->
-    let tbl = Hashtbl.create (String.Map.cardinal map + 32) in
-    String.Map.iteri map ~f:(Hashtbl.add tbl);
-    tbl
-
   let find_cstr cstrs loc name ctx values =
     match List.assoc cstrs name with
     | Some t ->
diff --git a/src/dsexp/dsexp0.ml b/src/dsexp/dsexp0.ml
deleted file mode 100644
index f8cbb38c..00000000
--- a/src/dsexp/dsexp0.ml
+++ /dev/null
@@ -1,7 +0,0 @@
-include Types.Sexp
-
-let atom_or_quoted_string s =
-  if Atom.is_valid_dune s then
-    Atom (Atom.of_string s)
-  else
-    Quoted_string s
diff --git a/src/dsexp/dsexp0.mli b/src/dsexp/dsexp0.mli
deleted file mode 100644
index 94c45ca5..00000000
--- a/src/dsexp/dsexp0.mli
+++ /dev/null
@@ -1,7 +0,0 @@
-type t = Types.Sexp.t =
-  | Atom of Atom.t
-  | Quoted_string of string
-  | List of t list
-  | Template of Types.Template.t
-
-val atom_or_quoted_string : string -> t
diff --git a/src/dsexp/types.ml b/src/dsexp/types.ml
index eee28b0a..5c129ac6 100644
--- a/src/dsexp/types.ml
+++ b/src/dsexp/types.ml
@@ -20,11 +20,3 @@ module Template = struct
     ; loc: Loc.t
     }
 end
-
-module Sexp = struct
-  type t =
-    | Atom of Atom.t
-    | Quoted_string of string
-    | List of t list
-    | Template of Template.t
-end
diff --git a/src/stdune/escape.ml b/src/stdune/escape.ml
index 76b186fc..830a9d88 100644
--- a/src/stdune/escape.ml
+++ b/src/stdune/escape.ml
@@ -1,3 +1,5 @@
+module String = StringLabels
+
 type quote =
   | Needs_quoting_with_length of int
   | No_quoting
diff --git a/src/stdune/exn.ml b/src/stdune/exn.ml
index 6e9be578..ead3de51 100644
--- a/src/stdune/exn.ml
+++ b/src/stdune/exn.ml
@@ -1,10 +1,10 @@
 type t = exn
 
-exception Code_error of Sexp0.t
+exception Code_error of Sexp.t
 
 exception Fatal_error of string
 
-exception Loc_error of Loc0.t * string
+exception Loc_error of Loc.t * string
 
 external raise         : exn -> _ = "%raise"
 external raise_notrace : exn -> _ = "%raise_notrace"
@@ -26,9 +26,9 @@ let protect ~f ~finally = protectx () ~f ~finally
 
 let code_error message vars =
   Code_error
-    (Sexp0.List (Sexp0.Atom message
-                :: List.map vars ~f:(fun (name, value) ->
-                  Sexp0.List [Sexp0.Atom name; value])))
+    (List (Atom message
+           :: List.map vars ~f:(fun (name, value) ->
+             Sexp.List [Atom name; value])))
   |> raise
 
 include
diff --git a/src/stdune/exn.mli b/src/stdune/exn.mli
index bc117c8c..d7e3e2ab 100644
--- a/src/stdune/exn.mli
+++ b/src/stdune/exn.mli
@@ -2,7 +2,7 @@
 
 (** An programming error, that should be reported upstream. The error message
     shouldn't try to be developer friendly rather than user friendly. *)
-exception Code_error of Sexp0.t
+exception Code_error of Sexp.t
 
 
 (* CR-soon diml:
@@ -14,14 +14,14 @@ exception Code_error of Sexp0.t
 (** A fatal error, that should be reported to the user in a nice way *)
 exception Fatal_error of string
 
-exception Loc_error of Loc0.t * string
+exception Loc_error of Loc.t * string
 
 val fatalf
-  :  ?loc:Loc0.t
+  :  ?loc:Loc.t
   -> ('a, unit, string, string, string, 'b) format6
   -> 'a
 
-val code_error : string -> (string * Sexp0.t) list -> _
+val code_error : string -> (string * Sexp.t) list -> _
 
 type t = exn
 
diff --git a/src/stdune/hashtbl.ml b/src/stdune/hashtbl.ml
index 3e8c41e5..1f599556 100644
--- a/src/stdune/hashtbl.ml
+++ b/src/stdune/hashtbl.ml
@@ -87,3 +87,14 @@ let fold  t ~init ~f = foldi t ~init ~f:(fun _ x -> f x)
 let iter t ~f = iter ~f t
 
 let keys t = foldi t ~init:[] ~f:(fun key _ acc -> key :: acc)
+
+let sexp_of_t (type key) f g t =
+  let module M =
+    Map.Make(struct
+      type t = key
+      let compare a b = Ordering.of_int (compare a b)
+    end)
+  in
+  Map.sexp_of_t M.to_list f g
+    (foldi t ~init:M.empty ~f:(fun key data acc ->
+       M.add acc key data))
diff --git a/src/stdune/hashtbl.mli b/src/stdune/hashtbl.mli
index e86e7b00..cf27722a 100644
--- a/src/stdune/hashtbl.mli
+++ b/src/stdune/hashtbl.mli
@@ -27,3 +27,5 @@ val foldi : ('a, 'b) t -> init:'c -> f:('a -> 'b -> 'c -> 'c) -> 'c
 val mem : ('a, _) t -> 'a -> bool
 
 val keys : ('a, _) t -> 'a list
+
+val sexp_of_t : ('a -> Sexp.t) -> ('b -> Sexp.t) -> ('a, 'b) t -> Sexp.t
diff --git a/src/stdune/int.ml b/src/stdune/int.ml
index 0e6b6ec1..c2e4f901 100644
--- a/src/stdune/int.ml
+++ b/src/stdune/int.ml
@@ -7,6 +7,7 @@ module T = struct
       Eq
     else
       Gt
+  let sexp_of_t = Sexp.To_sexp.int
 end
 
 include T
diff --git a/src/stdune/int.mli b/src/stdune/int.mli
index eeafb3dd..577146a0 100644
--- a/src/stdune/int.mli
+++ b/src/stdune/int.mli
@@ -1,5 +1,6 @@
 type t = int
 val compare : t -> t -> Ordering.t
+val sexp_of_t : t -> Sexp.t
 
 module Set : Set.S with type elt = t
 module Map : Map.S with type key = t
diff --git a/src/stdune/loc.ml b/src/stdune/loc.ml
index 3cb59375..5355a336 100644
--- a/src/stdune/loc.ml
+++ b/src/stdune/loc.ml
@@ -1,4 +1,4 @@
-type t = Loc0.t =
+type t =
   { start : Lexing.position
   ; stop  : Lexing.position
   }
@@ -45,7 +45,7 @@ let equal_position
       ; pos_bol = b_b; pos_cnum = c_b }
       =
       let open Int.Infix in
-      String.equal f_a f_b
+      Caml.String.equal f_a f_b
       && l_a = l_b
       && b_a = b_b
       && c_a = c_b
diff --git a/src/stdune/loc.mli b/src/stdune/loc.mli
index 52ae71c4..4893079b 100644
--- a/src/stdune/loc.mli
+++ b/src/stdune/loc.mli
@@ -1,4 +1,4 @@
-type t = Loc0.t =
+type t =
   { start : Lexing.position
   ; stop  : Lexing.position
   }
@@ -9,9 +9,9 @@ val none : t
 
 val of_lexbuf : Lexing.lexbuf -> t
 
-val sexp_of_t : t -> Sexp0.t
+val sexp_of_t : t -> Sexp.t
 
-val sexp_of_position_no_file : Lexing.position -> Sexp0.t
+val sexp_of_position_no_file : Lexing.position -> Sexp.t
 
 val equal : t -> t -> bool
 
diff --git a/src/stdune/loc0.ml b/src/stdune/loc0.ml
deleted file mode 100644
index 84c22b5b..00000000
--- a/src/stdune/loc0.ml
+++ /dev/null
@@ -1,4 +0,0 @@
-type t =
-  { start : Caml.Lexing.position
-  ; stop  : Caml.Lexing.position
-  }
diff --git a/src/stdune/map.ml b/src/stdune/map.ml
index e9e9e611..86c43bbc 100644
--- a/src/stdune/map.ml
+++ b/src/stdune/map.ml
@@ -143,3 +143,6 @@ module Make(Key : Comparable.S) : S with type key = Key.t = struct
   let superpose a b =
     union a b ~f:(fun _ _ y -> Some y)
 end
+
+let sexp_of_t to_list f g t =
+  Sexp.To_sexp.(list (pair f g)) (to_list t)
diff --git a/src/stdune/map.mli b/src/stdune/map.mli
index 5666e9ab..f3145923 100644
--- a/src/stdune/map.mli
+++ b/src/stdune/map.mli
@@ -1,3 +1,9 @@
 module type S = Map_intf.S
 
 module Make(Key : Comparable.S) : S with type key = Key.t
+
+val sexp_of_t
+  :  ('a -> ('b * 'c) list)
+  -> 'b Sexp.To_sexp.t
+  -> 'c Sexp.To_sexp.t
+  -> 'a Sexp.To_sexp.t
diff --git a/src/stdune/set.ml b/src/stdune/set.ml
index 4cc7b8d0..3ccf0ad9 100644
--- a/src/stdune/set.ml
+++ b/src/stdune/set.ml
@@ -45,3 +45,6 @@ module Make(Elt : Comparable.S) : S with type elt = Elt.t = struct
   let choose = choose_opt
   let split x t = split t x
 end
+
+let sexp_of_t to_list f t =
+  Sexp.To_sexp.list f (to_list t)
diff --git a/src/stdune/set.mli b/src/stdune/set.mli
index 71f6c0fc..3a03686f 100644
--- a/src/stdune/set.mli
+++ b/src/stdune/set.mli
@@ -1,3 +1,8 @@
 module type S = Set_intf.S
 
 module Make(Elt : Comparable.S) : S with type elt = Elt.t
+
+val sexp_of_t
+  :  ('a -> 'b list)
+  -> 'b Sexp.To_sexp.t
+  -> 'a Sexp.To_sexp.t
diff --git a/src/stdune/sexp.ml b/src/stdune/sexp.ml
index 873e4183..005e27fc 100644
--- a/src/stdune/sexp.ml
+++ b/src/stdune/sexp.ml
@@ -1,4 +1,8 @@
-type t = Sexp0.t =
+module Array = ArrayLabels
+module List = ListLabels
+module String = StringLabels
+
+type t =
   | Atom of string
   | List of t list
 
@@ -21,18 +25,11 @@ module To_sexp = struct
   let option f = function
     | None -> List []
     | Some x -> List [f x]
-  let string_set set = list string (String0.Set.to_list set)
-  let string_map f map = list (pair string f) (String0.Map.to_list map)
 
   let record l =
     List (List.map l ~f:(fun (n, v) -> List [Atom n; v]))
 
   let unknown _ = Atom "<unknown>"
-
-  let string_hashtbl f h =
-    string_map f
-      (Caml.Hashtbl.fold h ~init:String0.Map.empty ~f:(fun ~key ~data acc ->
-         String0.Map.add acc key data))
 end
 
 let rec to_string = function
diff --git a/src/stdune/sexp.mli b/src/stdune/sexp.mli
index 90768bf9..c299d18b 100644
--- a/src/stdune/sexp.mli
+++ b/src/stdune/sexp.mli
@@ -1,4 +1,4 @@
-type t = Sexp0.t =
+type t =
   | Atom of string
   | List of t list
 
diff --git a/src/stdune/sexp0.ml b/src/stdune/sexp0.ml
deleted file mode 100644
index a7151a9c..00000000
--- a/src/stdune/sexp0.ml
+++ /dev/null
@@ -1,3 +0,0 @@
-type t =
-  | Atom of string
-  | List of t list
diff --git a/src/stdune/sexp_intf.ml b/src/stdune/sexp_intf.ml
index ea2edd22..8954d017 100644
--- a/src/stdune/sexp_intf.ml
+++ b/src/stdune/sexp_intf.ml
@@ -10,7 +10,4 @@ module type Combinators = sig
   val list       : 'a t -> 'a list           t
   val array      : 'a t -> 'a array          t
   val option     : 'a t -> 'a option         t
-  val string_set : String0.Set.t             t
-  val string_map : 'a t -> 'a String0.Map.t  t
-  val string_hashtbl : 'a t -> (string, 'a) Caml.Hashtbl.t t
 end
diff --git a/src/stdune/string.ml b/src/stdune/string.ml
index 9bcb17d3..5816ff03 100644
--- a/src/stdune/string.ml
+++ b/src/stdune/string.ml
@@ -12,7 +12,14 @@ end
 
 include StringLabels
 
-include String0.T.Include
+let compare a b = Ordering.of_int (String.compare a b)
+
+module T = struct
+  type t = StringLabels.t
+  let compare = compare
+  let equal (x : t) (y : t) = x = y
+  let hash (s : t) = Hashtbl.hash s
+end
 
 let capitalize   = capitalize_ascii
 let uncapitalize = uncapitalize_ascii
@@ -195,16 +202,16 @@ let maybe_quoted s =
   else
     Printf.sprintf {|"%s"|} escaped
 
-module Set = String0.Set
+module Set = Set.Make(T)
 
 module Map = struct
-  include String0.Map
+  include Map.Make(T)
   let pp f fmt t =
     Format.pp_print_list (fun fmt (k, v) ->
       Format.fprintf fmt "@[<hov 2>(%s@ =@ %a)@]" k f v
     ) fmt (to_list t)
 end
-module Table = Hashtbl.Make(String0.T)
+module Table = Hashtbl.Make(T)
 
 let enumerate_gen s =
   let s = " " ^ s ^ " " in
diff --git a/src/stdune/string.mli b/src/stdune/string.mli
index b781d2b6..6ba31660 100644
--- a/src/stdune/string.mli
+++ b/src/stdune/string.mli
@@ -53,9 +53,9 @@ val enumerate_and : string list -> string
 (** Produces: "x, y or z" *)
 val enumerate_or  : string list -> string
 
-module Set : Set.S with type elt = t and type t = String0.Set.t
+module Set : Set.S with type elt = t
 module Map : sig
-  include Map.S with type key = t and type 'a t = 'a String0.Map.t
+  include Map.S with type key = t
 
   val pp : (Format.formatter -> 'a -> unit) -> Format.formatter -> 'a t -> unit
 end
diff --git a/src/stdune/string0.ml b/src/stdune/string0.ml
deleted file mode 100644
index e279fad7..00000000
--- a/src/stdune/string0.ml
+++ /dev/null
@@ -1,14 +0,0 @@
-module T = struct
-  type t = StringLabels.t
-
-  module Include = struct
-    let compare a b = Ordering.of_int (Caml.String.compare a b)
-    let equal (x : t) (y : t) = x = y
-    let hash (s : t) = Caml.Hashtbl.hash s
-  end
-
-  include Include
-end
-
-module Set = Set.Make(T)
-module Map = Map.Make(T)