diff --git a/doc/languages-frameworks/ocaml.section.md b/doc/languages-frameworks/ocaml.section.md
index d09e35c3a84b..d84b5fd80a1c 100644
--- a/doc/languages-frameworks/ocaml.section.md
+++ b/doc/languages-frameworks/ocaml.section.md
@@ -21,7 +21,7 @@ pkgs.mkShell {
   nativeBuildInputs = with ocamlPackages; [
     ocaml
     findlib
-    dune_2
+    pkgs.dune
     ocaml-lsp
   ];
   # dependencies
diff --git a/pkgs/applications/science/logic/abella/default.nix b/pkgs/applications/science/logic/abella/default.nix
index b8557f9e7bf3..9e3592b44445 100644
--- a/pkgs/applications/science/logic/abella/default.nix
+++ b/pkgs/applications/science/logic/abella/default.nix
@@ -4,6 +4,7 @@
   fetchurl,
   rsync,
   ocamlPackages,
+  dune,
 }:
 
 stdenv.mkDerivation (finalAttrs: {
@@ -19,10 +20,10 @@ stdenv.mkDerivation (finalAttrs: {
 
   nativeBuildInputs = [
     rsync
+    dune
   ]
   ++ (with ocamlPackages; [
     ocaml
-    dune_3
     menhir
     findlib
   ]);
diff --git a/pkgs/applications/science/logic/coq/default.nix b/pkgs/applications/science/logic/coq/default.nix
index c0275c97eafd..e3f5f7619fd6 100644
--- a/pkgs/applications/science/logic/coq/default.nix
+++ b/pkgs/applications/science/logic/coq/default.nix
@@ -13,6 +13,7 @@
   writeText,
   pkg-config,
   gnumake42,
+  dune,
   customOCamlPackages ? null,
   ocamlPackages_4_09,
   ocamlPackages_4_10,
@@ -130,7 +131,7 @@ let
     ocamlPackages.ocaml
     ocamlPackages.findlib
   ]
-  ++ lib.optional (coqAtLeast "8.14") ocamlPackages.dune_3;
+  ++ lib.optional (coqAtLeast "8.14") dune;
   ocamlPropagatedBuildInputs =
     [ ]
     ++ lib.optional (!coqAtLeast "8.10") ocamlPackages.camlp5
diff --git a/pkgs/applications/science/logic/easycrypt/default.nix b/pkgs/applications/science/logic/easycrypt/default.nix
index 27b39fd790c5..bbc37bb7dcd5 100644
--- a/pkgs/applications/science/logic/easycrypt/default.nix
+++ b/pkgs/applications/science/logic/easycrypt/default.nix
@@ -4,6 +4,7 @@
   darwin,
   fetchFromGitHub,
   ocamlPackages,
+  dune,
   why3,
   python3,
 }:
@@ -22,7 +23,7 @@ stdenv.mkDerivation rec {
   nativeBuildInputs =
     with ocamlPackages;
     [
-      dune_3
+      dune
       findlib
       menhir
       ocaml
diff --git a/pkgs/applications/science/logic/rocq-core/default.nix b/pkgs/applications/science/logic/rocq-core/default.nix
index 2a8a3d7be023..3d76ff2d0fda 100644
--- a/pkgs/applications/science/logic/rocq-core/default.nix
+++ b/pkgs/applications/science/logic/rocq-core/default.nix
@@ -11,6 +11,7 @@
   fetchurl,
   writeText,
   pkg-config,
+  dune,
   customOCamlPackages ? null,
   ocamlPackages_4_14,
   ncurses,
@@ -56,7 +57,7 @@ let
   ocamlNativeBuildInputs = [
     ocamlPackages.ocaml
     ocamlPackages.findlib
-    ocamlPackages.dune_3
+    dune
   ];
   ocamlPropagatedBuildInputs = [ ocamlPackages.zarith ];
   self = stdenv.mkDerivation {
diff --git a/pkgs/build-support/coq/default.nix b/pkgs/build-support/coq/default.nix
index 01719ce243a1..6bbd01da9d2d 100644
--- a/pkgs/build-support/coq/default.nix
+++ b/pkgs/build-support/coq/default.nix
@@ -6,6 +6,7 @@
   which,
   fetchzip,
   fetchurl,
+  dune,
 }@args:
 
 let
@@ -190,7 +191,7 @@ stdenv.mkDerivation (
       nativeBuildInputs =
         args.overrideNativeBuildInputs or (
           [ which ]
-          ++ optional useDune coq.ocamlPackages.dune_3
+          ++ optional useDune dune
           ++ optionals (useDune || mlPlugin) [
             coq.ocamlPackages.ocaml
             coq.ocamlPackages.findlib
diff --git a/pkgs/build-support/rocq/default.nix b/pkgs/build-support/rocq/default.nix
index d9429f0b23b5..8b86867d67d4 100644
--- a/pkgs/build-support/rocq/default.nix
+++ b/pkgs/build-support/rocq/default.nix
@@ -6,6 +6,7 @@
   which,
   fetchzip,
   fetchurl,
+  dune,
 }@args:
 
 let
@@ -174,7 +175,7 @@ stdenv.mkDerivation (
       nativeBuildInputs =
         args.overrideNativeBuildInputs or (
           [ which ]
-          ++ optional useDune rocq-core.ocamlPackages.dune_3
+          ++ optional useDune dune
           ++ optionals (useDune || mlPlugin) [
             rocq-core.ocamlPackages.ocaml
             rocq-core.ocamlPackages.findlib
diff --git a/pkgs/by-name/ac/acgtk/package.nix b/pkgs/by-name/ac/acgtk/package.nix
index 38c494ae8301..ba2b29b42281 100644
--- a/pkgs/by-name/ac/acgtk/package.nix
+++ b/pkgs/by-name/ac/acgtk/package.nix
@@ -4,6 +4,7 @@
   fetchFromGitLab,
   fetchpatch,
   ocamlPackages,
+  dune,
 }:
 
 stdenv.mkDerivation {
@@ -39,7 +40,7 @@ stdenv.mkDerivation {
     menhir
     ocaml
     findlib
-    dune_3
+    dune
   ];
 
   buildInputs = with ocamlPackages; [
diff --git a/pkgs/by-name/do/docfd/package.nix b/pkgs/by-name/do/docfd/package.nix
index ed37a05fdd39..98d49517c486 100644
--- a/pkgs/by-name/do/docfd/package.nix
+++ b/pkgs/by-name/do/docfd/package.nix
@@ -4,7 +4,7 @@
   stdenv,
   fetchFromGitHub,
   python3,
-  dune_3,
+  dune,
   makeWrapper,
   pandoc,
   poppler-utils,
@@ -30,7 +30,7 @@ ocamlPackages.buildDunePackage rec {
 
   nativeBuildInputs = [
     python3
-    dune_3
+    dune
     makeWrapper
   ];
 
diff --git a/pkgs/by-name/du/dune/package.nix b/pkgs/by-name/du/dune/package.nix
new file mode 100644
index 000000000000..9dfc90173f12
--- /dev/null
+++ b/pkgs/by-name/du/dune/package.nix
@@ -0,0 +1,58 @@
+{
+  lib,
+  stdenv,
+  fetchurl,
+  ocamlPackages,
+  version ? "3.20.2",
+}:
+
+stdenv.mkDerivation {
+  pname = "dune";
+  inherit version;
+
+  src = fetchurl {
+    url =
+      let
+        sfx = lib.optionalString (lib.versions.major version == "2") "site-";
+      in
+      "https://github.com/ocaml/dune/releases/download/${version}/dune-${sfx}${version}.tbz";
+    hash =
+      {
+        "3.20.2" = "sha256-sahrLWC9tKi5u2hhvfL58opufLXYM86Br+zOue+cpUk=";
+        "2.9.3" = "sha256:1ml8bxym8sdfz25bx947al7cvsi2zg5lcv7x9w6xb01cmdryqr9y";
+      }
+      ."${version}";
+  };
+
+  nativeBuildInputs = with ocamlPackages; [
+    ocaml
+    findlib
+  ];
+
+  strictDeps = true;
+
+  buildFlags = [ "release" ];
+
+  dontAddPrefix = true;
+  dontAddStaticConfigureFlags = true;
+  configurePlatforms = [ ];
+
+  installFlags = [
+    "PREFIX=${placeholder "out"}"
+    "LIBDIR=$(OCAMLFIND_DESTDIR)"
+  ];
+
+  passthru.tests = {
+    inherit (ocamlPackages) ocaml-lsp dune-release;
+  };
+
+  meta = {
+    homepage = "https://dune.build/";
+    description = "Composable build system";
+    mainProgram = "dune";
+    changelog = "https://github.com/ocaml/dune/raw/${version}/CHANGES.md";
+    maintainers = [ lib.maintainers.vbgl ];
+    license = lib.licenses.mit;
+    inherit (ocamlPackages.ocaml.meta) platforms;
+  };
+}
diff --git a/pkgs/by-name/fr/framac/package.nix b/pkgs/by-name/fr/framac/package.nix
index b3ef7520555c..2aa780e9df47 100644
--- a/pkgs/by-name/fr/framac/package.nix
+++ b/pkgs/by-name/fr/framac/package.nix
@@ -8,6 +8,7 @@
   ocamlPackages,
   ltl2ba,
   coq,
+  dune,
   why3,
   gdk-pixbuf,
   wrapGAppsHook3,
@@ -64,11 +65,11 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [
     wrapGAppsHook3
+    dune
   ]
   ++ (with ocamlPackages; [
     ocaml
     findlib
-    dune_3
     menhir
   ]);
 
diff --git a/pkgs/by-name/ja/jasmin-compiler/package.nix b/pkgs/by-name/ja/jasmin-compiler/package.nix
index ea4c89f30ad7..81c386202ce9 100644
--- a/pkgs/by-name/ja/jasmin-compiler/package.nix
+++ b/pkgs/by-name/ja/jasmin-compiler/package.nix
@@ -2,8 +2,8 @@
   stdenv,
   lib,
   fetchurl,
-  dune_3,
   ocamlPackages,
+  dune,
   mpfr,
   ppl,
 }:
@@ -20,7 +20,7 @@ stdenv.mkDerivation (finalAttrs: {
   nativeBuildInputs = with ocamlPackages; [
     ocaml
     findlib
-    dune_3
+    dune
     menhir
     camlidl
     cmdliner
diff --git a/pkgs/development/compilers/haxe/default.nix b/pkgs/development/compilers/haxe/default.nix
index 6b921250bae9..b2d636fd488b 100644
--- a/pkgs/development/compilers/haxe/default.nix
+++ b/pkgs/development/compilers/haxe/default.nix
@@ -4,6 +4,7 @@
   fetchFromGitHub,
   coreutils,
   ocaml-ng,
+  dune,
   zlib,
   pcre,
   pcre2,
@@ -23,7 +24,6 @@ let
         ptmap
         camlp5
         sha
-        dune_3
         luv
         extlib
       ]
@@ -37,7 +37,6 @@ let
         ptmap
         camlp5
         sha
-        dune_3
         luv
         extlib-1-7-7
       ];
@@ -61,6 +60,7 @@ let
       buildInputs = [
         zlib
         neko
+        dune
       ]
       ++ (if lib.versionAtLeast version "4.3" then [ pcre2 ] else [ pcre ])
       ++ lib.optional (lib.versionAtLeast version "4.1") mbedtls_2
diff --git a/pkgs/development/coq-modules/itauto/default.nix b/pkgs/development/coq-modules/itauto/default.nix
index b7d9e74c9805..da5b40c2923a 100644
--- a/pkgs/development/coq-modules/itauto/default.nix
+++ b/pkgs/development/coq-modules/itauto/default.nix
@@ -4,6 +4,7 @@
   mkCoqDerivation,
   coq,
   stdlib,
+  dune,
   version ? null,
 }:
 
@@ -60,7 +61,7 @@
       nativeBuildInputs = with coq.ocamlPackages; [
         ocaml
         findlib
-        dune_3
+        dune
       ];
     }
   )
diff --git a/pkgs/development/ocaml-modules/ocamlc-loc/default.nix b/pkgs/development/ocaml-modules/ocamlc-loc/default.nix
index d5ac0d14796d..623291093305 100644
--- a/pkgs/development/ocaml-modules/ocamlc-loc/default.nix
+++ b/pkgs/development/ocaml-modules/ocamlc-loc/default.nix
@@ -1,14 +1,13 @@
 {
   lib,
   buildDunePackage,
-  dune_3,
+  dune,
   dyn,
 }:
 
 buildDunePackage {
   pname = "ocamlc-loc";
-  inherit (dune_3) src version;
-  duneVersion = "3";
+  inherit (dune) src version;
 
   dontAddPrefix = true;
 
@@ -17,8 +16,6 @@ buildDunePackage {
     rm -rf vendor/pp
   '';
 
-  minimalOCamlVersion = "4.08";
-
   propagatedBuildInputs = [ dyn ];
 
   meta = {
diff --git a/pkgs/development/ocaml-modules/ordering/default.nix b/pkgs/development/ocaml-modules/ordering/default.nix
index 7776c0462d05..e34d0b6ce948 100644
--- a/pkgs/development/ocaml-modules/ordering/default.nix
+++ b/pkgs/development/ocaml-modules/ordering/default.nix
@@ -1,14 +1,12 @@
-{ buildDunePackage, dune_3 }:
+{ buildDunePackage, dune }:
 
 buildDunePackage {
   pname = "ordering";
-  inherit (dune_3) version src;
-  duneVersion = "3";
-  minimalOCamlVersion = "4.08";
+  inherit (dune) version src;
 
   dontAddPrefix = true;
 
-  meta = dune_3.meta // {
+  meta = dune.meta // {
     description = "Element ordering";
   };
 }
diff --git a/pkgs/development/ocaml-modules/stdune/default.nix b/pkgs/development/ocaml-modules/stdune/default.nix
index bc880cf2125f..985462643b91 100644
--- a/pkgs/development/ocaml-modules/stdune/default.nix
+++ b/pkgs/development/ocaml-modules/stdune/default.nix
@@ -1,6 +1,6 @@
 {
   buildDunePackage,
-  dune_3,
+  dune,
   dyn,
   ordering,
   csexp,
@@ -8,8 +8,7 @@
 
 buildDunePackage {
   pname = "stdune";
-  inherit (dune_3) version src;
-  duneVersion = "3";
+  inherit (dune) version src;
 
   dontAddPrefix = true;
 
@@ -23,7 +22,7 @@ buildDunePackage {
     rm -r vendor/csexp
   '';
 
-  meta = dune_3.meta // {
+  meta = dune.meta // {
     description = "Dune's unstable standard library";
   };
 }
diff --git a/pkgs/development/ocaml-modules/xdg/default.nix b/pkgs/development/ocaml-modules/xdg/default.nix
index c88f2695e7f4..97bb3a99d98d 100644
--- a/pkgs/development/ocaml-modules/xdg/default.nix
+++ b/pkgs/development/ocaml-modules/xdg/default.nix
@@ -1,22 +1,18 @@
 {
   lib,
   buildDunePackage,
-  dune_3,
+  dune,
 }:
 
 buildDunePackage {
   pname = "xdg";
-  inherit (dune_3) src version;
-
-  duneVersion = "3";
-  minimalOCamlVersion = "4.08";
+  inherit (dune) src version;
 
   dontAddPrefix = true;
 
   meta = {
     description = "XDG Base Directory Specification";
-    inherit (dune_3.meta) homepage;
-    maintainers = [ ];
+    inherit (dune.meta) homepage maintainers;
     license = lib.licenses.mit;
   };
 }
diff --git a/pkgs/development/tools/analysis/flow/default.nix b/pkgs/development/tools/analysis/flow/default.nix
index 0ead2df091d8..0fb442737540 100644
--- a/pkgs/development/tools/analysis/flow/default.nix
+++ b/pkgs/development/tools/analysis/flow/default.nix
@@ -3,6 +3,7 @@
   stdenv,
   fetchFromGitHub,
   ocamlPackages,
+  dune,
 }:
 
 stdenv.mkDerivation rec {
@@ -27,7 +28,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = with ocamlPackages; [
     ocaml
-    dune_3
+    dune
     findlib
     ocamlbuild
   ];
diff --git a/pkgs/development/tools/ocaml/dune/2.nix b/pkgs/development/tools/ocaml/dune/2.nix
deleted file mode 100644
index 57963e140391..000000000000
--- a/pkgs/development/tools/ocaml/dune/2.nix
+++ /dev/null
@@ -1,48 +0,0 @@
-{
-  lib,
-  stdenv,
-  fetchurl,
-  ocaml,
-  findlib,
-}:
-
-if lib.versionOlder ocaml.version "4.08" then
-  throw "dune 2 is not available for OCaml ${ocaml.version}"
-else
-
-  stdenv.mkDerivation rec {
-    pname = "dune";
-    version = "2.9.3";
-
-    src = fetchurl {
-      url = "https://github.com/ocaml/dune/releases/download/${version}/dune-site-${version}.tbz";
-      sha256 = "sha256:1ml8bxym8sdfz25bx947al7cvsi2zg5lcv7x9w6xb01cmdryqr9y";
-    };
-
-    nativeBuildInputs = [
-      ocaml
-      findlib
-    ];
-    strictDeps = true;
-
-    buildFlags = [ "release" ];
-
-    dontAddPrefix = true;
-    dontAddStaticConfigureFlags = true;
-    configurePlatforms = [ ];
-
-    installFlags = [
-      "PREFIX=${placeholder "out"}"
-      "LIBDIR=$(OCAMLFIND_DESTDIR)"
-    ];
-
-    meta = {
-      homepage = "https://dune.build/";
-      description = "Composable build system";
-      mainProgram = "dune";
-      changelog = "https://github.com/ocaml/dune/raw/${version}/CHANGES.md";
-      maintainers = [ lib.maintainers.vbgl ];
-      license = lib.licenses.mit;
-      inherit (ocaml.meta) platforms;
-    };
-  }
diff --git a/pkgs/development/tools/ocaml/dune/3.nix b/pkgs/development/tools/ocaml/dune/3.nix
deleted file mode 100644
index 40c6b589ec03..000000000000
--- a/pkgs/development/tools/ocaml/dune/3.nix
+++ /dev/null
@@ -1,55 +0,0 @@
-{
-  lib,
-  stdenv,
-  fetchurl,
-  ocaml,
-  findlib,
-  ocaml-lsp,
-  dune-release,
-}:
-
-if lib.versionOlder ocaml.version "4.08" then
-  throw "dune 3 is not available for OCaml ${ocaml.version}"
-else
-
-  stdenv.mkDerivation rec {
-    pname = "dune";
-    version = "3.20.2";
-
-    src = fetchurl {
-      url = "https://github.com/ocaml/dune/releases/download/${version}/dune-${version}.tbz";
-      hash = "sha256-sahrLWC9tKi5u2hhvfL58opufLXYM86Br+zOue+cpUk=";
-    };
-
-    nativeBuildInputs = [
-      ocaml
-      findlib
-    ];
-
-    strictDeps = true;
-
-    buildFlags = [ "release" ];
-
-    dontAddPrefix = true;
-    dontAddStaticConfigureFlags = true;
-    configurePlatforms = [ ];
-
-    installFlags = [
-      "PREFIX=${placeholder "out"}"
-      "LIBDIR=$(OCAMLFIND_DESTDIR)"
-    ];
-
-    passthru.tests = {
-      inherit ocaml-lsp dune-release;
-    };
-
-    meta = {
-      homepage = "https://dune.build/";
-      description = "Composable build system";
-      mainProgram = "dune";
-      changelog = "https://github.com/ocaml/dune/raw/${version}/CHANGES.md";
-      maintainers = [ lib.maintainers.vbgl ];
-      license = lib.licenses.mit;
-      inherit (ocaml.meta) platforms;
-    };
-  }
diff --git a/pkgs/development/tools/ocaml/merlin/4.x.nix b/pkgs/development/tools/ocaml/merlin/4.x.nix
index 530c9c6ac829..51d46b00b681 100644
--- a/pkgs/development/tools/ocaml/merlin/4.x.nix
+++ b/pkgs/development/tools/ocaml/merlin/4.x.nix
@@ -3,7 +3,7 @@
   replaceVars,
   fetchurl,
   ocaml,
-  dune_3,
+  dune,
   buildDunePackage,
   yojson,
   csexp,
@@ -69,7 +69,7 @@ buildDunePackage {
     [
       (replaceVars (if old-patch then ./fix-paths.patch else ./fix-paths2.patch) {
         dot-merlin-reader = "${dot-merlin-reader}/bin/dot-merlin-reader";
-        dune = "${dune_3}/bin/dune";
+        dune = "${dune}/bin/dune";
       })
     ];
 
diff --git a/pkgs/tools/audio/liquidsoap/full.nix b/pkgs/tools/audio/liquidsoap/full.nix
index 9e1d921b3541..54ffcc4e3540 100644
--- a/pkgs/tools/audio/liquidsoap/full.nix
+++ b/pkgs/tools/audio/liquidsoap/full.nix
@@ -10,6 +10,7 @@
   awscli2,
   bubblewrap,
   curl,
+  dune,
   ffmpeg,
   yt-dlp,
   runtimePackages ? [
@@ -78,7 +79,7 @@ stdenv.mkDerivation {
     pkg-config
     which
     ocamlPackages.ocaml
-    ocamlPackages.dune_3
+    dune
     ocamlPackages.findlib
     ocamlPackages.menhir
   ];
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 3a4b3203986a..c3f7945f5e2f 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1889,7 +1889,13 @@ with pkgs;
 
   inherit (ocamlPackages) dot-merlin-reader;
 
-  inherit (ocamlPackages) dune_2 dune_3 dune-release;
+  inherit (ocamlPackages) dune-release;
+
+  dune_2 = callPackage ../by-name/du/dune/package.nix {
+    version = "2.9.3";
+  };
+
+  dune_3 = callPackage ../by-name/du/dune/package.nix { };
 
   dvc = with python3.pkgs; toPythonApplication dvc;
 
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index 1d8c79728cfe..b801108f60b9 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -464,10 +464,6 @@ let
 
         dum = callPackage ../development/ocaml-modules/dum { };
 
-        dune_2 = callPackage ../development/tools/ocaml/dune/2.nix { };
-
-        dune_3 = callPackage ../development/tools/ocaml/dune/3.nix { };
-
         dune-action-plugin = callPackage ../development/ocaml-modules/dune-action-plugin { };
 
         dune-build-info = callPackage ../development/ocaml-modules/dune-build-info { };
@@ -2249,6 +2245,8 @@ let
       // lib.optionalAttrs config.allowAliases {
         biocaml = throw "biocaml has been removed"; # 2025-06-04
         chacha = throw "chacha has been removed because it has been marked as broken since at least November 2024. It is now vendored inside mirage-crypto, consider using that instead."; # Added 2025-10-11
+        dune_2 = pkgs.dune_2; # Added 2025-12-08
+        dune_3 = pkgs.dune_3; # Added 2025-12-08
         gd4o = throw "ocamlPackages.gd4o is not maintained, use ocamlPackages.gd instead";
         ocaml-vdom = throw "2023-10-09: ocamlPackages.ocaml-vdom was renamed to ocamlPackages.vdom";
         ocaml_lwt = throw "ocamlPackages.ocaml_lwt has been renamed to ocamlPackages.lwt"; # Added 2025-12-05