diff --git a/CHANGES.md b/CHANGES.md
index 5643cc6e98..7a36b75d33 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,6 @@
 ## current
 
+- Remove dependency to base (@samoht #745)
 - fix opam files and dependencies
 - add GitHub Actions workflow (@smorimoto #739)
 - lwt_jsoo: Forward exceptions to caller when response is null (@mefyl #738)
diff --git a/cohttp-lwt-unix/test/test_parser.ml b/cohttp-lwt-unix/test/test_parser.ml
index 9d26fec911..000d1ea56b 100644
--- a/cohttp-lwt-unix/test/test_parser.ml
+++ b/cohttp-lwt-unix/test/test_parser.ml
@@ -276,7 +276,7 @@ let mutate_simple_req () =
       ~headers:(Header.init_with "foo" "bar")
       (Uri.of_string "/foo/bar")
   in
-  let req = Fieldslib.Field.fset Request.Fields.meth req `POST in
+  let req = { req with Request.meth = `POST } in
   write_req expected req
 
 let make_simple_res () =
diff --git a/cohttp.opam b/cohttp.opam
index 6cca69a75a..4a9995d4e1 100644
--- a/cohttp.opam
+++ b/cohttp.opam
@@ -33,15 +33,12 @@ doc: "https://mirage.github.io/ocaml-cohttp/"
 bug-reports: "https://github.com/mirage/ocaml-cohttp/issues"
 depends: [
   "ocaml" {>= "4.08"}
-  "dune" {>= "1.1.0"}
+  "dune" {>= "2.0.0"}
   "re" {>= "1.9.0"}
   "uri" {>= "2.0.0"}
   "uri-sexp"
-  "fieldslib"
   "sexplib0"
-  "ppx_fields_conv" {>= "v0.9.0"}
   "ppx_sexp_conv" {>= "v0.13.0"}
-  "ppx_compare" {>= "v0.13.0"}
   "stringext"
   "base64" {>= "3.1.0"}
   "fmt" {with-test}
diff --git a/cohttp/scripts/generate.ml b/cohttp/scripts/generate.ml
index b93d7059cc..0319761ed0 100644
--- a/cohttp/scripts/generate.ml
+++ b/cohttp/scripts/generate.ml
@@ -196,7 +196,7 @@ let output_type oc ~mli t =
       if i = 0 then append oc "  [ %s%s" c.constr doc
       else append oc "  | %s%s" c.constr doc)
     t.codes;
-  append oc "  ] [@@deriving compare, sexp]";
+  append oc "  ] [@@deriving sexp]";
   if mli then append oc "(** %s *)" (String.capitalize_ascii t.section);
   append oc ""
 
@@ -204,11 +204,9 @@ let output_status_types oc ~mli t =
   List.iter (output_type oc ~mli) t;
   append oc "type status = [";
   List.iter (fun t -> append oc "  | %s_status" t.section) t;
-  append oc "] [@@deriving compare, sexp]";
+  append oc "] [@@deriving sexp]";
   append oc "";
-  if not mli then append oc "let compare_int = Int.compare\n" else ();
-  append oc
-    "type status_code = [`Code of int | status ] [@@deriving compare, sexp]";
+  append oc "type status_code = [`Code of int | status ] [@@deriving sexp]";
   append oc ""
 
 let iter fn s = List.iter (fun s -> List.iter fn s.codes) s
@@ -284,7 +282,7 @@ let output_gen_types oc (_name, typ, gens) =
   append oc "type %s = [" typ;
   List.iter (fun { constr; _ } -> append oc "  | %s" constr) gens;
   append oc "  | `Other of string";
-  append oc "] [@@deriving compare, sexp]";
+  append oc "] [@@deriving sexp]";
   append oc ""
 
 let output_gen_convert oc ~mli (name, typ, gens) =
@@ -344,7 +342,6 @@ let meth = ("method", "meth", known_methods)
 let gen oc ~mli =
   append oc "(* Auto-Generated by 'ocaml generate.ml' *)";
   append oc "open! Sexplib0.Sexp_conv";
-  if not mli then append oc "open Ppx_compare_lib.Builtin";
   append oc "";
   output_gen_types oc version;
   output_gen_types oc meth;
diff --git a/cohttp/src/cookie.ml b/cohttp/src/cookie.ml
index 17ca9a43e3..89f1718c48 100644
--- a/cohttp/src/cookie.ml
+++ b/cohttp/src/cookie.ml
@@ -29,7 +29,14 @@ module Set_cookie_hdr = struct
     secure : bool;
     http_only : bool;
   }
-  [@@deriving fields, sexp]
+  [@@deriving sexp]
+
+  let cookie t = t.cookie
+  let expiration t = t.expiration
+  let domain t = t.domain
+  let path t = t.path
+  let secure t = t.secure
+  let http_only t = t.http_only
 
   (* Does not check the contents of name or value for ';', ',', '\s', or name[0]='$' *)
   let make ?(expiration = `Session) ?path ?domain ?(secure = false)
diff --git a/cohttp/src/cookie.mli b/cohttp/src/cookie.mli
index 59c43102d1..70a0a8ef62 100644
--- a/cohttp/src/cookie.mli
+++ b/cohttp/src/cookie.mli
@@ -44,7 +44,7 @@ module Set_cookie_hdr : sig
     secure : bool;
     http_only : bool;
   }
-  [@@deriving fields, sexp]
+  [@@deriving sexp]
   (** A header which a server sends to a client to request that the client
       returns the cookie in future requests, under certain conditions. *)
 
@@ -80,6 +80,8 @@ module Set_cookie_hdr : sig
 
   val secure : t -> bool
   (** Has the cookie's secure attribute been set? *)
+
+  val http_only : t -> bool
 end
 
 module Cookie_hdr : sig
diff --git a/cohttp/src/dune b/cohttp/src/dune
index 0846994375..c115ca1e61 100644
--- a/cohttp/src/dune
+++ b/cohttp/src/dune
@@ -17,9 +17,8 @@
  (public_name cohttp)
  (synopsis "Co-operative Client/Server HTTP library.")
  (preprocess
-  (pps ppx_compare ppx_fields_conv ppx_sexp_conv))
- (libraries ppx_compare.runtime-lib re stringext uri uri-sexp fieldslib
-   sexplib0 bytes base64))
+  (pps ppx_sexp_conv))
+ (libraries re stringext uri uri-sexp sexplib0 bytes base64))
 
 (ocamllex accept_lexer)
 
diff --git a/cohttp/src/link.ml b/cohttp/src/link.ml
index dbf284df65..0343df62d7 100644
--- a/cohttp/src/link.ml
+++ b/cohttp/src/link.ml
@@ -119,8 +119,11 @@ end
 
 module Ext = struct
   type 'a t = { charset : Charset.t; language : Language.t; value : 'a }
-  [@@deriving sexp, fields]
+  [@@deriving sexp]
 
+  let charset t = t.charset
+  let language t = t.language
+  let value t = t.value
   let make ?(charset = "") ?(language = "") value = { charset; language; value }
   let map f x = { x with value = f x.value }
 end
diff --git a/cohttp/src/request.ml b/cohttp/src/request.ml
index 0368051b43..215086a090 100644
--- a/cohttp/src/request.ml
+++ b/cohttp/src/request.ml
@@ -14,7 +14,6 @@
  *
   }}}*)
 
-open Ppx_compare_lib.Builtin
 open Sexplib0.Sexp_conv
 
 type t = {
@@ -25,8 +24,21 @@ type t = {
   version : Code.version;
   encoding : Transfer.encoding;
 }
-[@@deriving compare, fields, sexp]
-
+[@@deriving sexp]
+
+let compare x y =
+  match Header.compare x.headers y.headers with
+  | 0 ->
+      let headers = Header.init () in
+      Stdlib.compare { x with headers } { y with headers }
+  | i -> i
+
+let headers t = t.headers
+let meth t = t.meth
+let scheme t = t.scheme
+let resource t = t.resource
+let version t = t.version
+let encoding t = t.encoding
 let fixed_zero = Transfer.Fixed Int64.zero
 
 let guess_encoding ?(encoding = fixed_zero) headers =
diff --git a/cohttp/src/response.ml b/cohttp/src/response.ml
index b79e50d10f..b168ea7198 100644
--- a/cohttp/src/response.ml
+++ b/cohttp/src/response.ml
@@ -16,8 +16,6 @@
 
 open Sexplib0.Sexp_conv
 
-let compare_bool = Bool.compare
-
 type t = {
   encoding : Transfer.encoding;
   headers : Header.t;
@@ -25,7 +23,20 @@ type t = {
   status : Code.status_code;
   flush : bool;
 }
-[@@deriving compare, fields, sexp]
+[@@deriving sexp]
+
+let compare x y =
+  match Header.compare x.headers y.headers with
+  | 0 ->
+      let headers = Header.init () in
+      Stdlib.compare { x with headers } { y with headers }
+  | i -> i
+
+let headers t = t.headers
+let encoding t = t.encoding
+let version t = t.version
+let status t = t.status
+let flush t = t.flush
 
 let make ?(version = `HTTP_1_1) ?(status = `OK) ?(flush = false)
     ?(encoding = Transfer.Chunked) ?(headers = Header.init ()) () =
diff --git a/cohttp/src/s.ml b/cohttp/src/s.ml
index f25eb199c1..e09b15c719 100644
--- a/cohttp/src/s.ml
+++ b/cohttp/src/s.ml
@@ -86,7 +86,15 @@ module type Request = sig
     version : Code.version;  (** HTTP version, usually 1.1 *)
     encoding : Transfer.encoding;  (** transfer encoding of this HTTP request *)
   }
-  [@@deriving compare, fields, sexp]
+  [@@deriving sexp]
+
+  val headers : t -> Header.t
+  val meth : t -> Code.meth
+  val scheme : t -> string option
+  val resource : t -> string
+  val version : t -> Code.version
+  val encoding : t -> Transfer.encoding
+  val compare : t -> t -> int
 
   val make :
     ?meth:Code.meth ->
@@ -119,14 +127,15 @@ module type Response = sig
     status : Code.status_code;  (** HTTP status code of the response *)
     flush : bool;
   }
-  [@@deriving compare, fields, sexp]
-
-  (* The response creates by [make ~encoding ~headers ()] has an
-     encoding value determined from the content of [headers] or if no
-     proper header is present, using the value of [encoding]. Checked
-     headers are "content-lenght", "content-range" and
-     "transfer-encoding". The default value of [encoding] is
-     chunked. *)
+  [@@deriving sexp]
+
+  val encoding : t -> Transfer.encoding
+  val headers : t -> Header.t
+  val version : t -> Code.version
+  val status : t -> Code.status_code
+  val flush : t -> bool
+  val compare : t -> t -> int
+
   val make :
     ?version:Code.version ->
     ?status:Code.status_code ->
@@ -135,6 +144,11 @@ module type Response = sig
     ?headers:Header.t ->
     unit ->
     t
+  (** The response creates by [make ~encoding ~headers ()] has an encoding value
+      determined from the content of [headers] or if no proper header is
+      present, using the value of [encoding]. Checked headers are
+      "content-lenght", "content-range" and "transfer-encoding". The default
+      value of [encoding] is chunked. *)
 end
 
 module type Body = sig
diff --git a/cohttp/src/transfer.ml b/cohttp/src/transfer.ml
index 19d14db827..d31a30f74b 100644
--- a/cohttp/src/transfer.ml
+++ b/cohttp/src/transfer.ml
@@ -16,9 +16,7 @@
 
 open Sexplib0.Sexp_conv
 
-let compare_int64 = Int64.compare
-
-type encoding = Chunked | Fixed of int64 | Unknown [@@deriving compare, sexp]
+type encoding = Chunked | Fixed of int64 | Unknown [@@deriving sexp]
 type chunk = Chunk of string | Final_chunk of string | Done [@@deriving sexp]
 
 let string_of_encoding = function
diff --git a/cohttp/src/transfer.mli b/cohttp/src/transfer.mli
index cb97837885..63fda6c0b7 100644
--- a/cohttp/src/transfer.mli
+++ b/cohttp/src/transfer.mli
@@ -23,7 +23,7 @@ type encoding =
   | Chunked  (** dynamic chunked encoding *)
   | Fixed of int64  (** fixed size content *)
   | Unknown  (** unknown body size, which leads to best-effort *)
-[@@deriving compare, sexp]
+[@@deriving sexp]
 
 (** A chunk of body that also signals if there to more to arrive *)
 type chunk =
diff --git a/cohttp/test/dune b/cohttp/test/dune
index 4632550955..de9dd6bc91 100644
--- a/cohttp/test/dune
+++ b/cohttp/test/dune
@@ -1,6 +1,7 @@
 (executable
  (name test_accept)
  (modules test_accept)
+ (forbidden_libraries base)
  (libraries cohttp alcotest fmt))
 
 (rule
@@ -12,6 +13,7 @@
 (executable
  (name test_header)
  (modules test_header)
+ (forbidden_libraries base)
  (libraries cohttp alcotest fmt))
 
 (rule
@@ -23,6 +25,7 @@
 (executable
  (name test_request)
  (modules test_request)
+ (forbidden_libraries base)
  (libraries cohttp alcotest fmt))
 
 (rule
@@ -34,6 +37,7 @@
 (executable
  (name test_body)
  (modules test_body)
+ (forbidden_libraries base)
  (libraries cohttp alcotest fmt))
 
 (rule