diff --git a/src/action.ml b/src/action.ml
index ad8ac979..514bb1b0 100644
--- a/src/action.ml
+++ b/src/action.ml
@@ -1,5 +1,5 @@
 open Import
-open Sexp.Of_sexp
+open Dsexp.Of_sexp
 
 let ignore_loc k ~loc:_ = k
 
@@ -27,7 +27,7 @@ struct
 
   let t =
     let path = Path.t and string = String.t in
-    Sexp.Of_sexp.fix (fun t ->
+    Dsexp.Of_sexp.fix (fun t ->
       sum
         [ "run",
           (let%map prog = Program.t
@@ -268,7 +268,7 @@ module Prog = struct
 
   type t = (Path.t, Not_found.t) result
 
-  let t : t Sexp.Of_sexp.t = Sexp.Of_sexp.map Path.t ~f:Result.ok
+  let t : t Dsexp.Of_sexp.t = Dsexp.Of_sexp.map Path.t ~f:Result.ok
 
   let sexp_of_t = function
     | Ok s -> Path.sexp_of_t s
@@ -283,7 +283,7 @@ module rec Ast : Ast = Ast
 
 module String_with_sexp = struct
   type t = string
-  let t = Sexp.Of_sexp.string
+  let t = Dsexp.Of_sexp.string
   let sexp_of_t = Sexp.To_sexp.string
 end
 
diff --git a/src/action.mli b/src/action.mli
index 5815d07f..eaaf5da2 100644
--- a/src/action.mli
+++ b/src/action.mli
@@ -31,7 +31,7 @@ include Action_intf.Helpers
   with type string  := string
   with type t       := t
 
-val t : t Sexp.Of_sexp.t
+val t : t Dsexp.Of_sexp.t
 
 module For_shell : sig
   include Action_intf.Ast
@@ -39,7 +39,7 @@ module For_shell : sig
     with type path    := string
     with type string  := string
 
-  val sexp_of_t : t Sexp.To_sexp.t
+  val sexp_of_t : t Dsexp.To_sexp.t
 end
 
 (** Convert the action to a format suitable for printing *)
diff --git a/src/binary_kind.ml b/src/binary_kind.ml
index c209eda9..0324aa2e 100644
--- a/src/binary_kind.ml
+++ b/src/binary_kind.ml
@@ -6,7 +6,7 @@ type t =
   | Shared_object
 
 let t =
-  let open Sexp.Of_sexp in
+  let open Dsexp.Of_sexp in
   enum
     [ "exe"           , Exe
     ; "object"        , Object
diff --git a/src/binary_kind.mli b/src/binary_kind.mli
index b389c80d..cb53e0f5 100644
--- a/src/binary_kind.mli
+++ b/src/binary_kind.mli
@@ -7,7 +7,7 @@ type t =
   | Object
   | Shared_object
 
-val t : t Sexp.Of_sexp.t
+val t : t Dsexp.Of_sexp.t
 
 val sexp_of_t : t Sexp.To_sexp.t
 
diff --git a/src/build_system.ml b/src/build_system.ml
index 26ac4f58..974fa2e0 100644
--- a/src/build_system.ml
+++ b/src/build_system.ml
@@ -1275,7 +1275,7 @@ let update_universe t =
   Utils.Cached_digest.remove universe_file;
   let n =
     if Path.exists universe_file then
-      Sexp.Of_sexp.(parse int) Univ_map.empty
+      Dsexp.Of_sexp.(parse int) Univ_map.empty
         (Io.Dsexp.load ~mode:Single universe_file) + 1
     else
       0
diff --git a/src/config.mli b/src/config.mli
index 7e03b92e..a131a3b9 100644
--- a/src/config.mli
+++ b/src/config.mli
@@ -32,7 +32,7 @@ module Display : sig
     | Verbose  (** Display all commands fully     *)
     | Quiet    (** Only display errors            *)
 
-  val t : t Sexp.Of_sexp.t
+  val t : t Dsexp.Of_sexp.t
   val all : (string * t) list
 end
 
@@ -58,7 +58,7 @@ include S with type 'a field = 'a
 
 module Partial : S with type 'a field := 'a option
 
-val t : t Sexp.Of_sexp.t
+val t : t Dsexp.Of_sexp.t
 
 val merge : t -> Partial.t -> t
 
diff --git a/src/context.ml b/src/context.ml
index 6d55ae46..e0d87f79 100644
--- a/src/context.ml
+++ b/src/context.ml
@@ -452,7 +452,7 @@ let create_for_opam ?root ~env ~env_nodes ~targets ~profile ~switch ~name
     >>= fun s ->
     let vars =
       Usexp.parse_string ~fname:"<opam output>" ~mode:Single s
-      |> Sexp.Of_sexp.(parse (list (pair string string)) Univ_map.empty)
+      |> Dsexp.Of_sexp.(parse (list (pair string string)) Univ_map.empty)
       |> Env.Map.of_list_multi
       |> Env.Map.mapi ~f:(fun var values ->
         match List.rev values with
diff --git a/src/dune_env.mli b/src/dune_env.mli
index afe45c3a..5afbdfb6 100644
--- a/src/dune_env.mli
+++ b/src/dune_env.mli
@@ -18,7 +18,7 @@ module Stanza : sig
     ; rules : (pattern * config) list
     }
 
-  val t : t Sexp.Of_sexp.t
+  val t : t Dsexp.Of_sexp.t
 end
 
 type stanza +=
diff --git a/src/dune_project.ml b/src/dune_project.ml
index a5ac25d8..3d6d18bd 100644
--- a/src/dune_project.ml
+++ b/src/dune_project.ml
@@ -1,5 +1,5 @@
 open Import
-open Sexp.Of_sexp
+open Dsexp.Of_sexp
 
 module Kind = struct
   type t =
@@ -7,7 +7,7 @@ module Kind = struct
     | Jbuilder
 
   let sexp_of_t t =
-    Sexp.atom_or_quoted_string
+    Dsexp.atom_or_quoted_string
       (match t with
        | Dune -> "dune"
        | Jbuilder -> "jbuilder")
@@ -22,8 +22,8 @@ module Name : sig
 
   val to_string_hum : t -> string
 
-  val named_of_sexp : t Sexp.Of_sexp.t
-  val sexp_of_t : t Sexp.To_sexp.t
+  val named_of_sexp : t Dsexp.Of_sexp.t
+  val sexp_of_t : t Dsexp.To_sexp.t
 
   val encode : t -> string
   val decode : string -> t
@@ -59,9 +59,9 @@ end = struct
     | Anonymous p -> sprintf "<anonymous %s>" (Path.to_string_maybe_quoted p)
 
   let sexp_of_t = function
-    | Named s -> Sexp.To_sexp.string s
+    | Named s -> Dsexp.To_sexp.string s
     | Anonymous p ->
-      List [ Sexp.unsafe_atom_of_string "anonymous"
+      List [ Dsexp.unsafe_atom_of_string "anonymous"
            ; Path.sexp_of_t p
            ]
 
@@ -85,11 +85,11 @@ end = struct
       None
 
   let named_of_sexp =
-    Sexp.Of_sexp.plain_string (fun ~loc s ->
+    Dsexp.Of_sexp.plain_string (fun ~loc s ->
       if validate s then
         Named s
       else
-        Sexp.Of_sexp.of_sexp_errorf loc "invalid project name")
+        Dsexp.Of_sexp.of_sexp_errorf loc "invalid project name")
 
   let encode = function
     | Named     s -> s
@@ -132,7 +132,7 @@ module Project_file = struct
     }
 
   let sexp_of_t { file; exists } =
-    Sexp.To_sexp.(
+    Dsexp.To_sexp.(
       record
         [ "file", Path.sexp_of_t file
         ; "exists", bool exists
@@ -145,7 +145,7 @@ type t =
   ; root          : Path.Local.t
   ; version       : string option
   ; packages      : Package.t Package.Name.Map.t
-  ; stanza_parser : Stanza.t list Sexp.Of_sexp.t
+  ; stanza_parser : Stanza.t list Dsexp.Of_sexp.t
   ; project_file  : Project_file.t
   }
 
@@ -202,14 +202,14 @@ let append_to_project_file t str =
 module Extension = struct
   type t =
     { syntax  : Syntax.t
-    ; stanzas : Stanza.Parser.t list Sexp.Of_sexp.t
+    ; stanzas : Stanza.Parser.t list Dsexp.Of_sexp.t
     }
 
   type instance =
     { extension  : t
     ; version    : Syntax.Version.t
     ; loc        : Loc.t
-    ; parse_args : Stanza.Parser.t list Sexp.Of_sexp.t -> Stanza.Parser.t list
+    ; parse_args : Stanza.Parser.t list Dsexp.Of_sexp.t -> Stanza.Parser.t list
     }
 
   let extensions = Hashtbl.create 32
@@ -242,7 +242,7 @@ module Extension = struct
       if f name then
         let version = Syntax.greatest_supported_version ext.syntax in
         let parse_args p =
-          let open Sexp.Of_sexp in
+          let open Dsexp.Of_sexp in
           let dune_project_edited = ref false in
           parse (enter p) Univ_map.empty (List (Loc.of_pos __POS__, []))
           |> List.map ~f:(fun (name, p) ->
@@ -251,10 +251,10 @@ module Extension = struct
              if not !dune_project_edited then begin
                dune_project_edited := true;
                Project_file_edit.append project_file
-                 (Sexp.to_string ~syntax:Dune
-                    (List [ Sexp.atom "using"
-                          ; Sexp.atom name
-                          ; Sexp.atom (Syntax.Version.to_string version)
+                 (Dsexp.to_string ~syntax:Dune
+                    (List [ Dsexp.atom "using"
+                          ; Dsexp.atom name
+                          ; Dsexp.atom (Syntax.Version.to_string version)
                           ]))
              end;
              p))
@@ -278,17 +278,17 @@ let key =
   Univ_map.Key.create ~name:"dune-project"
     (fun { name; root; version; project_file; kind
          ; stanza_parser = _; packages = _ } ->
-      Sexp.To_sexp.record
+      Dsexp.To_sexp.record
         [ "name", Name.sexp_of_t name
         ; "root", Path.Local.sexp_of_t root
-        ; "version", Sexp.To_sexp.(option string) version
+        ; "version", Dsexp.To_sexp.(option string) version
         ; "project_file", Project_file.sexp_of_t project_file
         ; "kind", Kind.sexp_of_t kind
         ])
 
-let set t = Sexp.Of_sexp.set key t
+let set t = Dsexp.Of_sexp.set key t
 let get_exn () =
-  let open Sexp.Of_sexp in
+  let open Dsexp.Of_sexp in
   get key >>| function
   | Some t -> t
   | None ->
@@ -310,7 +310,7 @@ let anonymous = lazy (
   ; root          = get_local_path Path.root
   ; version       = None
   ; stanza_parser =
-      Sexp.Of_sexp.(set_many parsing_context (sum lang.data))
+      Dsexp.Of_sexp.(set_many parsing_context (sum lang.data))
   ; project_file  = { file = Path.relative Path.root filename; exists = false }
   })
 
@@ -375,14 +375,14 @@ let parse ~dir ~lang ~packages ~file =
            (lang.data ::
             List.map extensions ~f:(fun (ext : Extension.instance) ->
               ext.parse_args
-                (Sexp.Of_sexp.set_many parsing_context ext.extension.stanzas)))
+                (Dsexp.Of_sexp.set_many parsing_context ext.extension.stanzas)))
        in
        { kind = Dune
        ; name
        ; root = get_local_path dir
        ; version
        ; packages
-       ; stanza_parser = Sexp.Of_sexp.(set_many parsing_context (sum stanzas))
+       ; stanza_parser = Dsexp.Of_sexp.(set_many parsing_context (sum stanzas))
        ; project_file
        })
 
@@ -399,7 +399,7 @@ let make_jbuilder_project ~dir packages =
   ; version = None
   ; packages
   ; stanza_parser =
-      Sexp.Of_sexp.(set_many parsing_context (sum lang.data))
+      Dsexp.Of_sexp.(set_many parsing_context (sum lang.data))
   ; project_file = { file = Path.relative dir filename; exists = false }
   }
 
diff --git a/src/dune_project.mli b/src/dune_project.mli
index 2b073f2f..9380772d 100644
--- a/src/dune_project.mli
+++ b/src/dune_project.mli
@@ -22,7 +22,7 @@ module Name : sig
   (** Convert to a string that is suitable for human readable messages *)
   val to_string_hum : t -> string
 
-  val sexp_of_t : t -> Sexp.t
+  val sexp_of_t : t -> Dsexp.t
 
   (** Convert to/from an encoded string that is suitable to use in filenames *)
   val encode : t -> string
@@ -41,7 +41,7 @@ val packages : t -> Package.t Package.Name.Map.t
 val version : t -> string option
 val name : t -> Name.t
 val root : t -> Path.Local.t
-val stanza_parser : t -> Stanza.t list Sexp.Of_sexp.t
+val stanza_parser : t -> Stanza.t list Dsexp.Of_sexp.t
 
 module Lang : sig
   (** [register id stanzas_parser] register a new language. Users will
@@ -62,7 +62,7 @@ module Extension : sig
 
       in their [dune-project] file. [parser] is used to describe
       what [<args>] might be. *)
-  val register : Syntax.t -> Stanza.Parser.t list Sexp.Of_sexp.t -> unit
+  val register : Syntax.t -> Stanza.Parser.t list Dsexp.Of_sexp.t -> unit
 end
 
 (** Load a project description from the following directory. [files]
@@ -86,5 +86,5 @@ val ensure_project_file_exists : t -> unit
 val append_to_project_file : t -> string -> unit
 
 (** Set the project we are currently parsing dune files for *)
-val set : t -> ('a, 'k) Sexp.Of_sexp.parser -> ('a, 'k) Sexp.Of_sexp.parser
-val get_exn : unit -> (t, 'k) Sexp.Of_sexp.parser
+val set : t -> ('a, 'k) Dsexp.Of_sexp.parser -> ('a, 'k) Dsexp.Of_sexp.parser
+val get_exn : unit -> (t, 'k) Dsexp.Of_sexp.parser
diff --git a/src/file_tree.ml b/src/file_tree.ml
index 6cdab804..4824fbec 100644
--- a/src/file_tree.ml
+++ b/src/file_tree.ml
@@ -10,14 +10,14 @@ module Dune_file = struct
       | _ -> assert false
 
     let lexer = function
-      | Dune   -> Sexp.Lexer.token
-      | Jbuild -> Sexp.Lexer.jbuild_token
+      | Dune   -> Dsexp.Lexer.token
+      | Jbuild -> Dsexp.Lexer.jbuild_token
   end
 
   module Plain = struct
     type t =
       { path          : Path.t
-      ; mutable sexps : Sexp.Ast.t list
+      ; mutable sexps : Dsexp.Ast.t list
       }
   end
 
@@ -39,7 +39,7 @@ module Dune_file = struct
 
   let extract_ignored_subdirs =
     let stanza =
-      let open Sexp.Of_sexp in
+      let open Dsexp.Of_sexp in
       let sub_dir =
         plain_string (fun ~loc dn ->
           if Filename.dirname dn <> Filename.current_dir_name ||
@@ -58,9 +58,9 @@ module Dune_file = struct
     fun sexps ->
       let ignored_subdirs, sexps =
         List.partition_map sexps ~f:(fun sexp ->
-          match (sexp : Sexp.Ast.t) with
+          match (sexp : Dsexp.Ast.t) with
           | List (_, (Atom (_, A "ignored_subdirs") :: _)) ->
-            Left (Sexp.Of_sexp.parse stanza Univ_map.empty sexp)
+            Left (Dsexp.Of_sexp.parse stanza Univ_map.empty sexp)
           | _ -> Right sexp)
       in
       let ignored_subdirs =
diff --git a/src/inline_tests.ml b/src/inline_tests.ml
index 55d07341..dd94b04e 100644
--- a/src/inline_tests.ml
+++ b/src/inline_tests.ml
@@ -80,7 +80,7 @@ module Backend = struct
       }
 
     let to_sexp t =
-      let open Sexp.To_sexp in
+      let open Dsexp.To_sexp in
       let lib x = string (Lib.name x) in
       let f x = string (Lib.name x.lib) in
       ((1, 0),
diff --git a/src/install.ml b/src/install.ml
index 1609b704..44b17622 100644
--- a/src/install.ml
+++ b/src/install.ml
@@ -59,7 +59,7 @@ module Section = struct
     | _             -> None
 
   let t =
-    let open Sexp.Of_sexp in
+    let open Dsexp.Of_sexp in
     enum
       [ "lib"          , Lib
       ; "lib_root"     , Lib_root
diff --git a/src/install.mli b/src/install.mli
index 2ce0920a..5c653a05 100644
--- a/src/install.mli
+++ b/src/install.mli
@@ -19,7 +19,7 @@ module Section : sig
     | Man
     | Misc
 
-  val t : t Sexp.Of_sexp.t
+  val t : t Dsexp.Of_sexp.t
 
   (** [true] iff the executable bit should be set for files installed
       in this location. *)
diff --git a/src/installed_dune_file.ml b/src/installed_dune_file.ml
index 43fd6e83..1bf8f8ae 100644
--- a/src/installed_dune_file.ml
+++ b/src/installed_dune_file.ml
@@ -3,7 +3,7 @@ open Import
 let parse_sub_systems ~parsing_context sexps =
   List.filter_map sexps ~f:(fun sexp ->
     let name, ver, data =
-      Sexp.Of_sexp.(parse (triple string (located Syntax.Version.t) raw)
+      Dsexp.Of_sexp.(parse (triple string (located Syntax.Version.t) raw)
                       parsing_context) sexp
     in
     match Sub_system_name.get name with
@@ -12,7 +12,7 @@ let parse_sub_systems ~parsing_context sexps =
          correspond to plugins that are not in use in the current
          workspace. *)
       None
-    | Some name -> Some (name, (Sexp.Ast.loc sexp, ver, data)))
+    | Some name -> Some (name, (Dsexp.Ast.loc sexp, ver, data)))
   |> Sub_system_name.Map.of_list
   |> (function
     | Ok x -> x
@@ -32,10 +32,10 @@ let parse_sub_systems ~parsing_context sexps =
       | (_, _) ->
         Univ_map.add parsing_context (Syntax.key M.syntax) (snd version)
     in
-    M.T (Sexp.Of_sexp.parse M.parse parsing_context data))
+    M.T (Dsexp.Of_sexp.parse M.parse parsing_context data))
 
 let of_sexp =
-  let open Sexp.Of_sexp in
+  let open Dsexp.Of_sexp in
   let version =
     plain_string (fun ~loc -> function
       | "1" -> (0, 0)
@@ -64,40 +64,40 @@ let load fname =
        which point we can decide what lexer to use for the reset of
        the file. *)
     let state = ref 0 in
-    let lexer = ref Sexp.Lexer.token in
+    let lexer = ref Dsexp.Lexer.token in
     let lexer lb =
-      let token : Sexp.Lexer.Token.t = !lexer lb in
+      let token : Dsexp.Lexer.Token.t = !lexer lb in
       (match !state, token with
        | 0, Lparen -> state := 1
        | 1, Atom (A "dune") -> state := 2
-       | 2, Atom (A "1") -> state := 3; lexer := Sexp.Lexer.jbuild_token
-       | 2, Atom (A "2") -> state := 3; lexer := Sexp.Lexer.token
+       | 2, Atom (A "1") -> state := 3; lexer := Dsexp.Lexer.jbuild_token
+       | 2, Atom (A "2") -> state := 3; lexer := Dsexp.Lexer.token
        | 2, Atom (A version) ->
-         Loc.fail (Sexp.Loc.of_lexbuf lexbuf) "Unsupported version %S" version
+         Loc.fail (Dsexp.Loc.of_lexbuf lexbuf) "Unsupported version %S" version
        | 3, _ -> ()
        | _ ->
-         Loc.fail (Sexp.Loc.of_lexbuf lexbuf)
+         Loc.fail (Dsexp.Loc.of_lexbuf lexbuf)
            "This <lib>.dune file looks invalid, it should \
             contain a S-expression of the form (dune x.y ..)"
       );
       token
     in
-    Sexp.Of_sexp.parse of_sexp Univ_map.empty
-      (Sexp.Parser.parse ~lexer ~mode:Single lexbuf))
+    Dsexp.Of_sexp.parse of_sexp Univ_map.empty
+      (Dsexp.Parser.parse ~lexer ~mode:Single lexbuf))
 
 let gen ~(dune_version : Syntax.Version.t) confs =
   let sexps =
     Sub_system_name.Map.to_list confs
     |> List.map ~f:(fun (name, (ver, conf)) ->
       let (module M) = Dune_file.Sub_system_info.get name in
-      Sexp.List [ Sexp.atom (Sub_system_name.to_string name)
+      Dsexp.List [ Dsexp.atom (Sub_system_name.to_string name)
                 ; Syntax.Version.sexp_of_t ver
                 ; conf
                 ])
   in
-  Sexp.List
-    [ Sexp.unsafe_atom_of_string "dune"
-    ; Sexp.unsafe_atom_of_string
+  Dsexp.List
+    [ Dsexp.unsafe_atom_of_string "dune"
+    ; Dsexp.unsafe_atom_of_string
         (match dune_version with
          | (0, 0) -> "1"
          | (x, _) when x >= 1 -> "2"
diff --git a/src/mode.ml b/src/mode.ml
index fef3d670..1c5094f1 100644
--- a/src/mode.ml
+++ b/src/mode.ml
@@ -5,7 +5,7 @@ type t = Byte | Native
 let all = [Byte; Native]
 
 let t =
-  let open Sexp.Of_sexp in
+  let open Dsexp.Of_sexp in
   enum
     [ "byte"   , Byte
     ; "native" , Native
@@ -73,7 +73,7 @@ module Dict = struct
       ; native = List.mem Native ~set:l
       }
 
-    let t = Sexp.Of_sexp.(map (list t) ~f:of_list)
+    let t = Dsexp.Of_sexp.(map (list t) ~f:of_list)
 
     let is_empty t = not (t.byte || t.native)
 
diff --git a/src/mode.mli b/src/mode.mli
index d87542ca..1a8cefb1 100644
--- a/src/mode.mli
+++ b/src/mode.mli
@@ -2,7 +2,7 @@ open! Import
 
 type t = Byte | Native
 
-val t : t Sexp.Of_sexp.t
+val t : t Dsexp.Of_sexp.t
 
 val all : t list
 
@@ -35,7 +35,7 @@ module Dict : sig
   module Set : sig
 
     type nonrec t = bool t
-    val t : t Sexp.Of_sexp.t
+    val t : t Dsexp.Of_sexp.t
     val all : t
     val is_empty : t -> bool
     val to_list : t -> mode list
diff --git a/src/ordered_set_lang.ml b/src/ordered_set_lang.ml
index 604a53a5..df28d964 100644
--- a/src/ordered_set_lang.ml
+++ b/src/ordered_set_lang.ml
@@ -19,7 +19,7 @@ end
 type 'ast generic =
   { ast : 'ast
   ; loc : Loc.t option
-  ; context : Univ_map.t (* Parsing context for Sexp.Of_sexp.parse *)
+  ; context : Univ_map.t (* Parsing context for Dsexp.Of_sexp.parse *)
   }
 
 type ast_expanded = (Loc.t * string, Ast.expanded) Ast.t
@@ -235,14 +235,14 @@ let field ?(default=standard) ?check name =
   let t =
     match check with
     | None -> t
-    | Some x -> Sexp.Of_sexp.(>>>) x t
+    | Some x -> Dsexp.Of_sexp.(>>>) x t
   in
-  Sexp.Of_sexp.field name t ~default
+  Dsexp.Of_sexp.field name t ~default
 
 module Unexpanded = struct
   type ast = (String_with_vars.t, Ast.unexpanded) Ast.t
   type t = ast generic
-  let t : t Sexp.Of_sexp.t =
+  let t : t Dsexp.Of_sexp.t =
     let open Stanza.Of_sexp in
     let%map context = get_all
     and (loc, ast) =
@@ -275,9 +275,9 @@ module Unexpanded = struct
     let t =
       match check with
       | None -> t
-      | Some x -> Sexp.Of_sexp.(>>>) x t
+      | Some x -> Dsexp.Of_sexp.(>>>) x t
     in
-    Sexp.Of_sexp.field name t ~default
+    Dsexp.Of_sexp.field name t ~default
 
   let files t ~f =
     let rec loop acc (ast : ast) =
diff --git a/src/ordered_set_lang.mli b/src/ordered_set_lang.mli
index bb561ca6..865177d8 100644
--- a/src/ordered_set_lang.mli
+++ b/src/ordered_set_lang.mli
@@ -4,7 +4,7 @@
 open Import
 
 type t
-val t : t Sexp.Of_sexp.t
+val t : t Dsexp.Of_sexp.t
 
 (** Return the location of the set. [loc standard] returns [None] *)
 val loc : t -> Loc.t option
@@ -68,9 +68,9 @@ val is_standard : t -> bool
 
 val field
   :  ?default:t
-  -> ?check:unit Sexp.Of_sexp.t
+  -> ?check:unit Dsexp.Of_sexp.t
   -> string
-  -> t Sexp.Of_sexp.fields_parser
+  -> t Dsexp.Of_sexp.fields_parser
 
 module Unexpanded : sig
   type expanded = t
@@ -81,9 +81,9 @@ module Unexpanded : sig
 
   val field
     :  ?default:t
-    -> ?check:unit Sexp.Of_sexp.t
+    -> ?check:unit Dsexp.Of_sexp.t
     -> string
-    -> t Sexp.Of_sexp.fields_parser
+    -> t Dsexp.Of_sexp.fields_parser
 
   val has_special_forms : t -> bool
 
@@ -91,7 +91,7 @@ module Unexpanded : sig
   val files
     : t
     -> f:(String_with_vars.t -> Path.t)
-    -> Sexp.syntax * Path.Set.t
+    -> Dsexp.syntax * Path.Set.t
 
   (** Expand [t] using with the given file contents. [file_contents] is a map from
       filenames to their parsed contents. Every [(:include fn)] in [t] is replaced by
@@ -99,7 +99,7 @@ module Unexpanded : sig
   val expand
     :  t
     -> dir:Path.t
-    -> files_contents:Sexp.Ast.t Path.Map.t
+    -> files_contents:Dsexp.Ast.t Path.Map.t
     -> f:(String_with_vars.t -> Value.t list)
     -> expanded
 
diff --git a/src/package.ml b/src/package.ml
index af79aae1..6695554c 100644
--- a/src/package.ml
+++ b/src/package.ml
@@ -15,7 +15,7 @@ module Name = struct
 
   let pp fmt t = Format.pp_print_string fmt (to_string t)
 
-  let t = Sexp.Of_sexp.(map string ~f:of_string)
+  let t = Dsexp.Of_sexp.(map string ~f:of_string)
 
   module Infix = Comparable.Operators(T)
 end
diff --git a/src/package.mli b/src/package.mli
index 35ee0768..1b1709c6 100644
--- a/src/package.mli
+++ b/src/package.mli
@@ -13,7 +13,7 @@ module Name : sig
 
   include Interned.S with type t := t
 
-  val t : t Sexp.Of_sexp.t
+  val t : t Dsexp.Of_sexp.t
 
   module Infix : Comparable.OPS with type t = t
 end
diff --git a/src/preprocessing.ml b/src/preprocessing.ml
index 81f2c7b0..9fa7d146 100644
--- a/src/preprocessing.ml
+++ b/src/preprocessing.ml
@@ -194,7 +194,7 @@ module Jbuild_driver = struct
       in
       Sexp.parse_string ~mode:Single ~fname:"<internal>" info
         ~lexer:Sexp.Lexer.jbuild_token
-      |> Sexp.Of_sexp.parse Driver.Info.parse parsing_context
+      |> Dsexp.Of_sexp.parse Driver.Info.parse parsing_context
     in
     (Pp.of_string name,
      { info
diff --git a/src/promotion.ml b/src/promotion.ml
index 00c2255c..99a60f12 100644
--- a/src/promotion.ml
+++ b/src/promotion.ml
@@ -7,23 +7,23 @@ module File = struct
     }
 
   (* XXX these sexp converters will be useful for the dump command *)
-  let _t =
-    let open Sexp.Of_sexp in
-    peek_exn >>= function
-    | List (_, [_; Atom (_, A "as"); _]) ->
-      enter
-        (let%map src = Path.t
-         and () = junk
-         and dst = Path.t
-         in
-         { src; dst })
-    | sexp ->
-      Sexp.Of_sexp.of_sexp_errorf (Sexp.Ast.loc sexp)
-        "(<file> as <file>) expected"
+  (* let _t =
+   *   let open Dsexp.Of_sexp in
+   *   peek_exn >>= function
+   *   | List (_, [_; Atom (_, A "as"); _]) ->
+   *     enter
+   *       (let % map src = Path.t
+   *        and () = junk
+   *        and dst = Path.t
+   *        in
+   *        { src; dst })
+   *   | sexp ->
+   *     Dsexp.Of_sexp.of_sexp_errorf (Sexp.Ast.loc sexp)
+   *       "(<file> as <file>) expected" *)
 
-  let _sexp_of_t { src; dst } =
-    Sexp.List [Path.sexp_of_t src; Sexp.unsafe_atom_of_string "as";
-               Path.sexp_of_t dst]
+  (* let _sexp_of_t { src; dst } =
+   *   Sexp.List [Path.sexp_of_t src; Sexp.unsafe_atom_of_string "as";
+   *              Path.sexp_of_t dst] *)
 
   let db : t list ref = ref []
 
diff --git a/src/report_error.ml b/src/report_error.ml
index 7832aa8d..fde677d8 100644
--- a/src/report_error.ml
+++ b/src/report_error.ml
@@ -44,7 +44,7 @@ let report_with_backtrace exn =
       in
       let pp ppf = Format.fprintf ppf "@{<error>Error@}: %s\n" msg in
       { p with loc = Some loc; pp }
-    | Sexp.Of_sexp.Of_sexp (loc, msg, hint') ->
+    | Dsexp.Of_sexp.Of_sexp (loc, msg, hint') ->
       let loc =
         { loc with
           start = { loc.start with pos_fname = !map_fname loc.start.pos_fname }
@@ -53,7 +53,7 @@ let report_with_backtrace exn =
       let pp ppf = Format.fprintf ppf "@{<error>Error@}: %s%s\n" msg
                      (match hint' with
                       | None -> ""
-                      | Some { Sexp.Of_sexp. on; candidates } ->
+                      | Some { Dsexp.Of_sexp. on; candidates } ->
                         hint on candidates)
       in
       { p with loc = Some loc; pp }
diff --git a/src/stanza.ml b/src/stanza.ml
index c59d2d6c..45fd931c 100644
--- a/src/stanza.ml
+++ b/src/stanza.ml
@@ -3,7 +3,7 @@ open Stdune
 type t = ..
 
 module Parser = struct
-  type nonrec t = string * t list Sexp.Of_sexp.t
+  type nonrec t = string * t list Dsexp.Of_sexp.t
 end
 
 let syntax =
@@ -13,7 +13,7 @@ let syntax =
     ]
 
 module File_kind = struct
-  type t = Sexp.syntax = Jbuild | Dune
+  type t = Dsexp.syntax = Jbuild | Dune
 
   let of_syntax = function
     | (0, _) -> Jbuild
@@ -21,11 +21,11 @@ module File_kind = struct
 end
 
 let file_kind () =
-  let open Sexp.Of_sexp in
+  let open Dsexp.Of_sexp in
   Syntax.get_exn syntax >>| File_kind.of_syntax
 
 module Of_sexp = struct
-  include Sexp.Of_sexp
+  include Dsexp.Of_sexp
 
   exception Parens_no_longer_necessary of Loc.t
 
@@ -88,7 +88,7 @@ module Of_sexp = struct
     match Univ_map.find parsing_context (Syntax.key syntax) with
     | Some (0, _) ->
       let last = Option.value_exn (List.last entries) in
-      Loc.warn (Sexp.Ast.loc last)
+      Loc.warn (Dsexp.Ast.loc last)
         "Field %S is present several times, previous occurrences are ignored."
         name
     | _ ->
diff --git a/src/stanza.mli b/src/stanza.mli
index f8b7249c..fefdb1fe 100644
--- a/src/stanza.mli
+++ b/src/stanza.mli
@@ -9,7 +9,7 @@ module Parser : sig
 
       Each stanza in a configuration file might produce several values
       of type [t], hence the [t list] here. *)
-  type nonrec t = string * t list Sexp.Of_sexp.t
+  type nonrec t = string * t list Dsexp.Of_sexp.t
 end
 
 (** Syntax identifier for the Dune language. [(0, X)] correspond to
@@ -18,21 +18,21 @@ end
 val syntax : Syntax.t
 
 module File_kind : sig
-  type t = Sexp.syntax = Jbuild | Dune
+  type t = Dsexp.syntax = Jbuild | Dune
 
   val of_syntax : Syntax.Version.t -> t
 end
 
 (** Whether we are parsing a [jbuild] or [dune] file. *)
-val file_kind : unit -> (File_kind.t, _) Sexp.Of_sexp.parser
+val file_kind : unit -> (File_kind.t, _) Dsexp.Of_sexp.parser
 
-(** Overlay for [Sexp.Of_sexp] where lists and records don't require
+(** Overlay for [Dsexp.Of_sexp] where lists and records don't require
    an extra level of parentheses in Dune files.
 
     Additionally, [field_xxx] functions only warn about duplicated
     fields in jbuild files, for backward compatibility. *)
 module Of_sexp : sig
-  include module type of struct include Sexp.Of_sexp end
+  include module type of struct include Dsexp.Of_sexp end
 
   val record : 'a fields_parser -> 'a t
   val list : 'a t -> 'a list t
diff --git a/src/stdune/path.ml b/src/stdune/path.ml
index 3683a9b1..cf66df35 100644
--- a/src/stdune/path.ml
+++ b/src/stdune/path.ml
@@ -34,10 +34,10 @@ let explode_path =
 module External : sig
   type t
 
+  include Dsexp.Sexpable with type t := t
+
   val compare : t -> t -> Ordering.t
   val compare_val : t -> t -> Ordering.t
-  val t : t Sexp.Of_sexp.t
-  val sexp_of_t : t Sexp.To_sexp.t
   val to_string : t -> string
   val of_string : string -> t
   val relative : t -> string -> t
@@ -72,9 +72,9 @@ end = struct
     make t
 
   let sexp_of_t t = Sexp.To_sexp.string (to_string t)
-  let t = Sexp.Of_sexp.plain_string (fun ~loc t ->
+  let t = Dsexp.Of_sexp.plain_string (fun ~loc t ->
     if Filename.is_relative t then
-      Sexp.Of_sexp.of_sexp_errorf loc "Absolute path expected"
+      Dsexp.Of_sexp.of_sexp_errorf loc "Absolute path expected"
     else
       of_string t)
 
@@ -130,8 +130,7 @@ end
 module Local : sig
   type t
 
-  val t : t Sexp.Of_sexp.t
-  val sexp_of_t : t Sexp.To_sexp.t
+  include Dsexp.Sexpable with type t := t
   val root : t
   val is_root : t -> bool
   val compare : t -> t -> Ordering.t
@@ -292,7 +291,7 @@ end = struct
       relative root s ?error_loc
 
   let t =
-    Sexp.Of_sexp.plain_string (fun ~loc:error_loc s ->
+    Dsexp.Of_sexp.plain_string (fun ~loc:error_loc s ->
       of_string s ~error_loc)
 
   let rec mkdir_p t =
@@ -608,7 +607,7 @@ let of_string ?error_loc s =
       make_local_path (Local.of_string s ?error_loc)
 
 let t =
-  let open Sexp.Of_sexp in
+  let open Dsexp.Of_sexp in
   if_list
     ~then_:
       (sum
diff --git a/src/stdune/path.mli b/src/stdune/path.mli
index 4e2c1c0a..1196551c 100644
--- a/src/stdune/path.mli
+++ b/src/stdune/path.mli
@@ -26,8 +26,7 @@ end
 
 type t
 
-val t : t Sexp.Of_sexp.t
-val sexp_of_t : t Sexp.To_sexp.t
+include Dsexp.Sexpable with type t := t
 
 val compare : t -> t -> Ordering.t
 (** a directory is smaller than its descendants *)
diff --git a/src/stdune/sexp.mli b/src/stdune/sexp.mli
new file mode 100644
index 00000000..e9401001
--- /dev/null
+++ b/src/stdune/sexp.mli
@@ -0,0 +1,10 @@
+include module type of struct include Usexp end with module Loc := Usexp.Loc
+
+module To_sexp : sig
+  type sexp = t
+  include Sexp_intf.Combinators with type 'a t = 'a -> t
+
+  val record : (string * sexp) list -> sexp
+
+  val unknown : _ t
+end with type sexp := t
diff --git a/src/string_with_vars.ml b/src/string_with_vars.ml
index f41d580f..652f14a1 100644
--- a/src/string_with_vars.ml
+++ b/src/string_with_vars.ml
@@ -95,7 +95,7 @@ end = struct
 end
 
 let t =
-  let open Sexp.Of_sexp in
+  let open Dsexp.Of_sexp in
   let jbuild =
     raw >>| function
     | Template _ as t ->
@@ -104,14 +104,14 @@ let t =
         ]
     | Atom(loc, A s) -> Jbuild.parse s ~loc ~quoted:false
     | Quoted_string (loc, s) -> Jbuild.parse s ~loc ~quoted:true
-    | List (loc, _) -> Sexp.Of_sexp.of_sexp_error loc "Atom expected"
+    | List (loc, _) -> Dsexp.Of_sexp.of_sexp_error loc "Atom expected"
   in
   let dune =
     raw >>| function
     | Template t -> t
     | Atom(loc, A s) -> literal ~quoted:false ~loc s
     | Quoted_string (loc, s) -> literal ~quoted:true ~loc s
-    | List (loc, _) -> Sexp.Of_sexp.of_sexp_error loc "Unexpected list"
+    | List (loc, _) -> Dsexp.Of_sexp.of_sexp_error loc "Unexpected list"
   in
   let template_parser = Stanza.Of_sexp.switch_file_kind ~jbuild ~dune in
   let%map syntax_version = Syntax.get_exn Stanza.syntax
@@ -203,7 +203,7 @@ module Var = struct
 
   let to_string = string_of_var
 
-  let sexp_of_t t = Sexp.atom (to_string t)
+  let sexp_of_t t = Dsexp.atom (to_string t)
 
   let with_name t ~name =
     { t with name }
diff --git a/src/string_with_vars.mli b/src/string_with_vars.mli
index 4a3736bd..fdd23e47 100644
--- a/src/string_with_vars.mli
+++ b/src/string_with_vars.mli
@@ -8,7 +8,7 @@ open Import
 type t
 (** A sequence of text and variables. *)
 
-val t : t Sexp.Of_sexp.t
+val t : t Dsexp.Of_sexp.t
 (** [t ast] takes an [ast] sexp and returns a string-with-vars.  This
     function distinguishes between unquoted variables — such as ${@} —
     and quoted variables — such as "${@}". *)
diff --git a/src/syntax.ml b/src/syntax.ml
index aaa25212..343c979a 100644
--- a/src/syntax.ml
+++ b/src/syntax.ml
@@ -18,8 +18,8 @@ module Version = struct
 
   let sexp_of_t t = Sexp.unsafe_atom_of_string (to_string t)
 
-  let t : t Sexp.Of_sexp.t =
-    let open Sexp.Of_sexp in
+  let t : t Dsexp.Of_sexp.t =
+    let open Dsexp.Of_sexp in
     raw >>| function
     | Atom (loc, A s) -> begin
         try
@@ -123,7 +123,7 @@ let greatest_supported_version t =
 
 let key t = t.key
 
-open Sexp.Of_sexp
+open Dsexp.Of_sexp
 
 let set t ver parser =
   set t.key ver parser
diff --git a/src/versioned_file.mli b/src/versioned_file.mli
index 6d8833c6..2b7cceec 100644
--- a/src/versioned_file.mli
+++ b/src/versioned_file.mli
@@ -30,14 +30,14 @@ module type S = sig
   (** [load fn ~f] loads a versioned file. It parses the first line,
       looks up the language, checks that the version is supported and
       parses the rest of the file with [f]. *)
-  val load : Path.t -> f:(Lang.Instance.t -> 'a Sexp.Of_sexp.t) -> 'a
+  val load : Path.t -> f:(Lang.Instance.t -> 'a Dsexp.Of_sexp.t) -> 'a
 
   (** Parse the contents of a versioned file after the first line has
       been read. *)
   val parse_contents
     :  Lexing.lexbuf
     -> Dune_lexer.first_line
-    -> f:(Lang.Instance.t -> 'a Sexp.Of_sexp.t)
+    -> f:(Lang.Instance.t -> 'a Dsexp.Of_sexp.t)
     -> 'a
 end
 
diff --git a/src/workspace.ml b/src/workspace.ml
index 8ccc0a9a..bea16325 100644
--- a/src/workspace.ml
+++ b/src/workspace.ml
@@ -122,7 +122,7 @@ module Context = struct
         (* jbuild-workspace files *)
         (peek_exn >>= function
          | List (_, List _ :: _) ->
-           Sexp.Of_sexp.record (Opam.t ~profile ~x) >>| fun x -> Opam x
+           Dsexp.Of_sexp.record (Opam.t ~profile ~x) >>| fun x -> Opam x
          | _ -> t ~profile ~x)
       ~dune:(t ~profile ~x)
 
diff --git a/test/unit-tests/dune_file.mlt b/test/unit-tests/dune_file.mlt
index ecf75c77..4bd28a6f 100644
--- a/test/unit-tests/dune_file.mlt
+++ b/test/unit-tests/dune_file.mlt
@@ -9,7 +9,7 @@ let sexp_pp = Sexp.pp Dune;;
 
 (* Dune_file.Executables.Link_mode.t *)
 let test s =
-  Sexp.Of_sexp.parse Dune_file.Executables.Link_mode.t Univ_map.empty
+  Dsexp.Of_sexp.parse Dune_file.Executables.Link_mode.t Univ_map.empty
     (Sexp.parse_string ~fname:"" ~mode:Sexp.Parser.Mode.Single s)
 [%%expect{|
 val sexp_pp : Format.formatter -> Usexp.t -> unit = <fun>
diff --git a/test/unit-tests/sexp.mlt b/test/unit-tests/sexp.mlt
index 7776cec6..196612cc 100644
--- a/test/unit-tests/sexp.mlt
+++ b/test/unit-tests/sexp.mlt
@@ -1,6 +1,6 @@
 (* -*- tuareg -*- *)
 open Stdune;;
-open Sexp.Of_sexp;;
+open Dsexp.Of_sexp;;
 
 let print_loc ppf (_ : Sexp.Loc.t) = Format.pp_print_string ppf "<loc>";;
 #install_printer print_loc;;