diff --git a/pkgs/development/ocaml-modules/janestreet/0.14.nix b/pkgs/development/ocaml-modules/janestreet/0.14.nix
index 800b1c1e531a..cee30da45c9e 100644
--- a/pkgs/development/ocaml-modules/janestreet/0.14.nix
+++ b/pkgs/development/ocaml-modules/janestreet/0.14.nix
@@ -313,6 +313,7 @@ with self;
     meta.description = "A library for building dynamic webapps, using Js_of_ocaml";
     buildInputs = [ js_of_ocaml-ppx ];
     propagatedBuildInputs = [ async_js incr_map incr_select virtual_dom ];
+    patches = [ ./incr_dom_jsoo_4_0.patch ];
   };
 
   incr_map = janePackage {
diff --git a/pkgs/development/ocaml-modules/janestreet/incr_dom_jsoo_4_0.patch b/pkgs/development/ocaml-modules/janestreet/incr_dom_jsoo_4_0.patch
new file mode 100644
index 000000000000..4e7a45ce96d3
--- /dev/null
+++ b/pkgs/development/ocaml-modules/janestreet/incr_dom_jsoo_4_0.patch
@@ -0,0 +1,24 @@
+diff --git a/src/js_misc.ml b/src/js_misc.ml
+index 65f7b44..bfef103 100644
+--- a/src/js_misc.ml
++++ b/src/js_misc.ml
+@@ -28,17 +28,11 @@ type rows_or_columns =
+ [@@deriving sexp, bin_io, variants, compare]
+ 
+ let innerHeight () =
+-  Js.Optdef.case
+-    Dom_html.window##.innerHeight
+-    (fun () -> Dom_html.document##.documentElement##.clientHeight)
+-    Fn.id
++  Dom_html.window##.innerHeight
+ ;;
+ 
+ let innerWidth () =
+-  Js.Optdef.case
+-    Dom_html.window##.innerWidth
+-    (fun () -> Dom_html.document##.documentElement##.clientWidth)
+-    Fn.id
++  Dom_html.window##.innerWidth
+ ;;
+ 
+ let element_is_in_viewport (elt : Dom_html.element Js.t) =
diff --git a/pkgs/development/ocaml-modules/ocsigen-toolkit/default.nix b/pkgs/development/ocaml-modules/ocsigen-toolkit/default.nix
index 12a92c5be399..60a07d30d059 100644
--- a/pkgs/development/ocaml-modules/ocsigen-toolkit/default.nix
+++ b/pkgs/development/ocaml-modules/ocsigen-toolkit/default.nix
@@ -5,7 +5,7 @@
 stdenv.mkDerivation rec {
  pname = "ocsigen-toolkit";
  name = "ocaml${ocaml.version}-${pname}-${version}";
- version = "3.1.1";
+ version = "3.2.0";
 
  propagatedBuildInputs = [ calendar js_of_ocaml-ppx_deriving_json eliom ];
  nativeBuildInputs = [ ocaml findlib opaline eliom ];
@@ -25,7 +25,7 @@ stdenv.mkDerivation rec {
     owner = "ocsigen";
     repo = pname;
     rev = version;
-    sha256 = "sha256:1fm0vvccmjib9yj5m2760vhzb4z3392swlprp51az53g3vk4q218";
+    sha256 = "sha256:13n0y8a80bl94la4lnp9dr2x7b8plhm17g9zgf0l6x42g3886pw7";
   };
 
   meta = {
diff --git a/pkgs/development/tools/ocaml/js_of_ocaml/compiler.nix b/pkgs/development/tools/ocaml/js_of_ocaml/compiler.nix
index 82d84c819dd2..7805ca264035 100644
--- a/pkgs/development/tools/ocaml/js_of_ocaml/compiler.nix
+++ b/pkgs/development/tools/ocaml/js_of_ocaml/compiler.nix
@@ -5,12 +5,12 @@
 
 buildDunePackage rec {
   pname = "js_of_ocaml-compiler";
-  version = "3.11.0";
+  version = "4.0.0";
   useDune2 = true;
 
   src = fetchurl {
     url = "https://github.com/ocsigen/js_of_ocaml/releases/download/${version}/js_of_ocaml-${version}.tbz";
-    sha256 = "sha256:0flws9mw0yjfw4d8d3y3k408mivy2xgky70xk1br3iqs4zksz38m";
+    sha256 = "sha256:0pj9jjrmi0xxrzmygv4b5whsibw1jxy3wgibmws85x5jwlczh0nz";
   };
 
   nativeBuildInputs = [ menhir ];
diff --git a/pkgs/development/tools/ocaml/js_of_ocaml/ocamlbuild.nix b/pkgs/development/tools/ocaml/js_of_ocaml/ocamlbuild.nix
index c67d05c15038..fa9ff95b0fd2 100644
--- a/pkgs/development/tools/ocaml/js_of_ocaml/ocamlbuild.nix
+++ b/pkgs/development/tools/ocaml/js_of_ocaml/ocamlbuild.nix
@@ -1,13 +1,26 @@
-{ buildDunePackage, js_of_ocaml-compiler
+{ lib, buildDunePackage, fetchFromGitHub
 , ocamlbuild
 }:
 
-buildDunePackage {
+buildDunePackage rec {
   pname = "js_of_ocaml-ocamlbuild";
-
-  inherit (js_of_ocaml-compiler) version src meta useDune2;
+  version = "4.0.0";
 
   minimalOCamlVersion = "4.02";
 
+  src = fetchFromGitHub {
+    owner = "ocsigen";
+    repo = pname;
+    rev = "852302c8f35b946e2ec275c529a79e46d8749be6";
+    sha256 = "sha256:03ayvakvbh4wi4dwcgd7r9y8ka8cv3d59hb81yk2dxyd94bln145";
+  };
+
   propagatedBuildInputs = [ ocamlbuild ];
+
+  meta = {
+    description = "An ocamlbuild plugin to compile to JavaScript";
+    license = lib.licenses.lgpl2Only;
+    maintainers = [ lib.maintainers.vbgl ];
+    inherit (src.meta) homepage;
+  };
 }