diff --git a/pkgs/development/ocaml-modules/charInfo_width/default.nix b/pkgs/development/ocaml-modules/charInfo_width/default.nix
index 5b9814cea69a..aaf181104548 100644
--- a/pkgs/development/ocaml-modules/charInfo_width/default.nix
+++ b/pkgs/development/ocaml-modules/charInfo_width/default.nix
@@ -3,7 +3,7 @@
 buildDunePackage rec {
   pname = "charInfo_width";
   version = "1.1.0";
-  useDune2 = true;
+  duneVersion = "3";
   src = fetchzip {
     url = "https://bitbucket.org/zandoye/charinfo_width/get/${version}.tar.bz2";
     sha256 = "19mnq9a1yr16srqs8n6hddahr4f9d2gbpmld62pvlw1ps7nfrp9w";
diff --git a/pkgs/development/ocaml-modules/zed/default.nix b/pkgs/development/ocaml-modules/zed/default.nix
index db9efd22749f..2922a57244b9 100644
--- a/pkgs/development/ocaml-modules/zed/default.nix
+++ b/pkgs/development/ocaml-modules/zed/default.nix
@@ -7,14 +7,12 @@ let
       {
         version = "3.2.0";
         sha256 = "sha256-6yKHE30nVFXo8hGdCx+GO4VYYGbi802aMdN2XuYMJ7w=";
-        duneVersion = "3";
         propagatedBuildInputs = [ react result uchar uutf uucp uuseg ];
       }
     else
       {
         version = "3.1.0";
         sha256 = "04vr1a94imsghm98iigc35rhifsz0rh3qz2qm0wam2wvp6vmrx0p";
-        duneVersion = "2";
         propagatedBuildInputs = [ charInfo_width react ];
       };
 in
@@ -22,7 +20,9 @@ in
 buildDunePackage rec {
   pname = "zed";
 
-  inherit (switch) version duneVersion propagatedBuildInputs;
+  inherit (switch) version propagatedBuildInputs;
+
+  duneVersion = "3";
 
   src = fetchFromGitHub {
     owner = "ocaml-community";