diff --git a/pkgs/development/ocaml-modules/csv/csvtool.nix b/pkgs/development/ocaml-modules/csv/csvtool.nix
index 12c0dfa160e..05d9a440f9c 100644
--- a/pkgs/development/ocaml-modules/csv/csvtool.nix
+++ b/pkgs/development/ocaml-modules/csv/csvtool.nix
@@ -4,7 +4,9 @@ let inherit (ocamlPackages) buildDunePackage csv uutf; in
 
 buildDunePackage {
   pname = "csvtool";
-  inherit (csv) src version useDune2;
+  inherit (csv) src version;
+
+  duneVersion = "3";
 
   buildInputs = [ csv uutf ];
 
diff --git a/pkgs/development/ocaml-modules/csv/default.nix b/pkgs/development/ocaml-modules/csv/default.nix
index d4c3d72a6d8..7510dcede3a 100644
--- a/pkgs/development/ocaml-modules/csv/default.nix
+++ b/pkgs/development/ocaml-modules/csv/default.nix
@@ -9,7 +9,11 @@ buildDunePackage rec {
     sha256 = "13m9n8mdss6jfbiw7d5bybxn4n85vmg4zw7dc968qrgjfy0w9zhk";
   };
 
-  useDune2 = true;
+  preConfigure = ''
+    substituteInPlace src/dune --replace '(libraries bytes)' ""
+  '';
+
+  duneVersion = "3";
 
   meta = {
     description = "A pure OCaml library to read and write CSV files";
diff --git a/pkgs/development/ocaml-modules/csv/lwt.nix b/pkgs/development/ocaml-modules/csv/lwt.nix
index c90dc019b9d..8e91decfd65 100644
--- a/pkgs/development/ocaml-modules/csv/lwt.nix
+++ b/pkgs/development/ocaml-modules/csv/lwt.nix
@@ -1,14 +1,16 @@
-{ lib, buildDunePackage, ocaml, csv, ocaml_lwt }:
-
-if lib.versionOlder ocaml.version "4.02"
-then throw "csv-lwt is not available for OCaml ${ocaml.version}"
-else
+{ lib, buildDunePackage, csv, lwt }:
 
 buildDunePackage {
   pname = "csv-lwt";
-  inherit (csv) src version useDune2 meta;
+  inherit (csv) src version meta;
 
-  propagatedBuildInputs = [ csv ocaml_lwt ];
+  preConfigure = ''
+    substituteInPlace lwt/dune --replace '(libraries   bytes' '(libraries '
+  '';
 
-  doCheck = lib.versionAtLeast ocaml.version "4.03";
+  duneVersion = "3";
+
+  propagatedBuildInputs = [ csv lwt ];
+
+  doCheck = true;
 }