diff --git a/doc/languages-frameworks/ocaml.section.md b/doc/languages-frameworks/ocaml.section.md
index 47035551d418..e4813d7dd2d4 100644
--- a/doc/languages-frameworks/ocaml.section.md
+++ b/doc/languages-frameworks/ocaml.section.md
@@ -38,8 +38,8 @@ Here is a simple package example.
 
 - It uses the `fetchFromGitHub` fetcher to get its source.
 
-- `useDune2 = true` ensures that the latest version of Dune is used for the
-  build (this may become the default value in a future release).
+- `useDune2 = true` ensures that Dune version 2 is used for the
+  build (this is the default; set to `false` to use Dune version 1).
 
 - It sets the optional `doCheck` attribute such that tests will be run with
   `dune runtest -p angstrom` after the build (`dune build -p angstrom`) is
diff --git a/pkgs/build-support/ocaml/dune.nix b/pkgs/build-support/ocaml/dune.nix
index 6bdec501630e..18e8784cfab3 100644
--- a/pkgs/build-support/ocaml/dune.nix
+++ b/pkgs/build-support/ocaml/dune.nix
@@ -2,7 +2,7 @@
 
 { pname, version, nativeBuildInputs ? [], enableParallelBuilding ? true, ... }@args:
 
-let Dune = if args.useDune2 or false then dune_2 else dune_1; in
+let Dune = if args.useDune2 or true then dune_2 else dune_1; in
 
 if (args ? minimumOCamlVersion && ! lib.versionAtLeast ocaml.version args.minimumOCamlVersion) ||
    (args ? minimalOCamlVersion && ! lib.versionAtLeast ocaml.version args.minimalOCamlVersion)
diff --git a/pkgs/development/ocaml-modules/facile/default.nix b/pkgs/development/ocaml-modules/facile/default.nix
index 8834de53a8fa..df228603e9f4 100644
--- a/pkgs/development/ocaml-modules/facile/default.nix
+++ b/pkgs/development/ocaml-modules/facile/default.nix
@@ -4,6 +4,8 @@ buildDunePackage rec {
   pname = "facile";
   version = "1.1.4";
 
+  useDune2 = false;
+
   src = fetchurl {
     url = "https://github.com/Emmanuel-PLF/facile/releases/download/${version}/facile-${version}.tbz";
     sha256 = "0jqrwmn6fr2vj2rrbllwxq4cmxykv7zh0y4vnngx29f5084a04jp";
diff --git a/pkgs/development/ocaml-modules/genspio/default.nix b/pkgs/development/ocaml-modules/genspio/default.nix
index db3c42bca36c..963cd1dab138 100644
--- a/pkgs/development/ocaml-modules/genspio/default.nix
+++ b/pkgs/development/ocaml-modules/genspio/default.nix
@@ -6,6 +6,8 @@ buildDunePackage rec {
   pname = "genspio";
   version = "0.0.2";
 
+  useDune2 = false;
+
   src = fetchFromGitHub {
     owner = "hammerlab";
     repo = pname;
@@ -13,7 +15,7 @@ buildDunePackage rec {
     sha256 = "0cp6p1f713sfv4p2r03bzvjvakzn4ili7hf3a952b3w1k39hv37x";
   };
 
-  minimumOCamlVersion = "4.03";
+  minimalOCamlVersion = "4.03";
 
   propagatedBuildInputs = [ nonstd sosa ];
 
diff --git a/pkgs/development/ocaml-modules/janestreet/janePackage.nix b/pkgs/development/ocaml-modules/janestreet/janePackage.nix
index 63c4a900fced..da2687576015 100644
--- a/pkgs/development/ocaml-modules/janestreet/janePackage.nix
+++ b/pkgs/development/ocaml-modules/janestreet/janePackage.nix
@@ -5,7 +5,9 @@
 buildDunePackage (args // {
   inherit version buildInputs;
 
-  minimumOCamlVersion = "4.04";
+  useDune2 = false;
+
+  minimalOCamlVersion = "4.04";
 
   src = fetchFromGitHub {
     owner = "janestreet";
diff --git a/pkgs/development/ocaml-modules/janestreet/janePackage_0_12.nix b/pkgs/development/ocaml-modules/janestreet/janePackage_0_12.nix
index 3d280a509acc..5b9186835701 100644
--- a/pkgs/development/ocaml-modules/janestreet/janePackage_0_12.nix
+++ b/pkgs/development/ocaml-modules/janestreet/janePackage_0_12.nix
@@ -5,6 +5,8 @@
 buildDunePackage (args // {
   inherit version;
 
+  useDune2 = false;
+
   minimalOCamlVersion = "4.07";
 
   src = fetchFromGitHub {
diff --git a/pkgs/development/ocaml-modules/lwt/camlp4.nix b/pkgs/development/ocaml-modules/lwt/camlp4.nix
index 88bb3d6759a0..e48d7cfa185a 100644
--- a/pkgs/development/ocaml-modules/lwt/camlp4.nix
+++ b/pkgs/development/ocaml-modules/lwt/camlp4.nix
@@ -11,7 +11,9 @@ buildDunePackage rec {
     sha256 = "1lv8z6ljfy47yvxmwf5jrvc5d3dc90r1n291x53j161sf22ddrk9";
   };
 
-  minimumOCamlVersion = "4.02";
+  useDune2 = false;
+
+  minimalOCamlVersion = "4.02";
 
   propagatedBuildInputs = [ camlp4 ];
 
diff --git a/pkgs/development/ocaml-modules/nonstd/default.nix b/pkgs/development/ocaml-modules/nonstd/default.nix
index 9de535154eeb..82b1feed540b 100644
--- a/pkgs/development/ocaml-modules/nonstd/default.nix
+++ b/pkgs/development/ocaml-modules/nonstd/default.nix
@@ -4,7 +4,9 @@ buildDunePackage rec {
   pname = "nonstd";
   version = "0.0.3";
 
-  minimumOCamlVersion = "4.02";
+  useDune2 = false;
+
+  minimalOCamlVersion = "4.02";
 
   src = fetchzip {
     url = "https://bitbucket.org/smondet/${pname}/get/${pname}.${version}.tar.gz";
diff --git a/pkgs/development/tools/ocaml/js_of_ocaml/camlp4.nix b/pkgs/development/tools/ocaml/js_of_ocaml/camlp4.nix
index a08aaac832e3..39f6d5f7aa2d 100644
--- a/pkgs/development/tools/ocaml/js_of_ocaml/camlp4.nix
+++ b/pkgs/development/tools/ocaml/js_of_ocaml/camlp4.nix
@@ -6,6 +6,8 @@ buildDunePackage rec {
   version = "3.2.1";
   pname = "js_of_ocaml-camlp4";
 
+  useDune2 = false;
+
   src = fetchFromGitHub {
     owner = "ocsigen";
     repo = "js_of_ocaml";