diff --git a/pkgs/development/ocaml-modules/fieldslib/default.nix b/pkgs/development/ocaml-modules/fieldslib/default.nix
new file mode 100644
index 00000000000..28b83d3af46
--- /dev/null
+++ b/pkgs/development/ocaml-modules/fieldslib/default.nix
@@ -0,0 +1,25 @@
+{ stdenv, fetchurl, ocaml, findlib, ocaml_typeconv, camlp4 }:
+
+assert stdenv.lib.versionOlder "4.00" (stdenv.lib.getVersion ocaml);
+
+stdenv.mkDerivation {
+  name = "ocaml-fieldslib-109.20.03";
+
+  src = fetchurl {
+    url = https://ocaml.janestreet.com/ocaml-core/109.20.00/individual/fieldslib-109.20.03.tar.gz;
+    sha256 = "1dkzk0wf26rhvji80dz1r56dp6x9zqrnp87wldd4pj56jli94vir";
+  };
+
+  buildInputs = [ ocaml findlib ];
+  propagatedBuildInputs = [ ocaml_typeconv camlp4 ];
+
+  createFindlibDestdir = true;
+
+  meta = with stdenv.lib; {
+    homepage = https://ocaml.janestreet.com/;
+    description = "OCaml syntax extension to define first class values representing record fields, to get and set record fields, iterate and fold over all fields of a record and create new record values";
+    license = licenses.asl20;
+    maintainers = [ maintainers.vbgl ];
+    platforms = ocaml.meta.platforms;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 6fef28741a0..2e80ec3f08e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -3634,6 +3634,8 @@ let
 
     eliom = callPackage ../development/ocaml-modules/eliom { };
 
+    fieldslib = callPackage ../development/ocaml-modules/fieldslib { };
+
     findlib = callPackage ../development/tools/ocaml/findlib { };
 
     fix = callPackage ../development/ocaml-modules/fix { };