diff --git a/pkgs/development/ocaml-modules/async_extra/default.nix b/pkgs/development/ocaml-modules/async_extra/default.nix
index 2d1e1dea69c..8689c0291c3 100644
--- a/pkgs/development/ocaml-modules/async_extra/default.nix
+++ b/pkgs/development/ocaml-modules/async_extra/default.nix
@@ -1,5 +1,5 @@
 {stdenv, buildOcaml, fetchurl, async_kernel, async_unix,
- bin_prot, core, custom_printf, fieldslib, herelib, pa_ounit,
+ bin_prot, core, custom_printf, fieldslib_p4, herelib, pa_ounit,
  pipebang, pa_test, sexplib}:
 
 buildOcaml rec {
@@ -15,7 +15,7 @@ buildOcaml rec {
 
   buildInputs = [ pa_test pa_ounit ];
   propagatedBuildInputs = [ async_kernel async_unix core bin_prot custom_printf
-                            fieldslib herelib pipebang sexplib ];
+                            fieldslib_p4 herelib pipebang sexplib ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async_extra;
diff --git a/pkgs/development/ocaml-modules/async_kernel/default.nix b/pkgs/development/ocaml-modules/async_kernel/default.nix
index 8c0d8d7c851..f850e461296 100644
--- a/pkgs/development/ocaml-modules/async_kernel/default.nix
+++ b/pkgs/development/ocaml-modules/async_kernel/default.nix
@@ -1,5 +1,5 @@
 {stdenv, buildOcaml, fetchurl, core_kernel,
- bin_prot, fieldslib, pa_ounit, pa_test,
+ bin_prot, fieldslib_p4, pa_ounit, pa_test,
  sexplib, herelib}:
 
 buildOcaml rec {
@@ -14,7 +14,7 @@ buildOcaml rec {
   };
 
   buildInputs = [ pa_test pa_ounit ];
-  propagatedBuildInputs = [ core_kernel bin_prot fieldslib herelib sexplib ];
+  propagatedBuildInputs = [ core_kernel bin_prot fieldslib_p4 herelib sexplib ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async_kernel;
diff --git a/pkgs/development/ocaml-modules/async_ssl/default.nix b/pkgs/development/ocaml-modules/async_ssl/default.nix
index 527d56ceaa0..cc4f5ba32c9 100644
--- a/pkgs/development/ocaml-modules/async_ssl/default.nix
+++ b/pkgs/development/ocaml-modules/async_ssl/default.nix
@@ -1,5 +1,5 @@
 {stdenv, buildOcaml, fetchurl, async, comparelib, core, ctypes, openssl,
- fieldslib, herelib, pa_bench, pa_ounit, pipebang, pa_test, sexplib}:
+ fieldslib_p4, herelib, pa_bench, pa_ounit, pipebang, pa_test, sexplib}:
 
 buildOcaml rec {
   name = "async_ssl";
@@ -13,7 +13,7 @@ buildOcaml rec {
   };
 
   buildInputs = [ pa_bench pa_test ];
-  propagatedBuildInputs = [ ctypes async comparelib core fieldslib pa_ounit
+  propagatedBuildInputs = [ ctypes async comparelib core fieldslib_p4 pa_ounit
                             herelib pipebang sexplib openssl ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/async_unix/default.nix b/pkgs/development/ocaml-modules/async_unix/default.nix
index 81fbd6a9918..11965f3f35f 100644
--- a/pkgs/development/ocaml-modules/async_unix/default.nix
+++ b/pkgs/development/ocaml-modules/async_unix/default.nix
@@ -1,5 +1,5 @@
 {stdenv, buildOcaml, fetchurl, async_kernel,
- bin_prot, comparelib, core, fieldslib, herelib, pa_ounit,
+ bin_prot, comparelib, core, fieldslib_p4, herelib, pa_ounit,
  pipebang, pa_test, sexplib}:
 
 buildOcaml rec {
@@ -16,7 +16,7 @@ buildOcaml rec {
   hasSharedObjects = true;
   buildInputs = [ pa_ounit ];
   propagatedBuildInputs = [ async_kernel core bin_prot comparelib
-                            fieldslib herelib pipebang pa_test sexplib ];
+                            fieldslib_p4 herelib pipebang pa_test sexplib ];
 
    meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async_unix;
diff --git a/pkgs/development/ocaml-modules/cohttp/default.nix b/pkgs/development/ocaml-modules/cohttp/default.nix
index 9a30a5e4615..0fa44a2cd7f 100644
--- a/pkgs/development/ocaml-modules/cohttp/default.nix
+++ b/pkgs/development/ocaml-modules/cohttp/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, cmdliner, re, uri, fieldslib, sexplib, conduit,
+{stdenv, buildOcaml, fetchurl, cmdliner, re, uri, fieldslib_p4, sexplib, conduit,
  stringext, base64, magic-mime, ounit, alcotest, lwt ? null,
  async ? null, async_ssl ? null}:
 
@@ -14,7 +14,7 @@ buildOcaml rec {
   };
 
   buildInputs = [ alcotest ];
-  propagatedBuildInputs = [ cmdliner re uri fieldslib sexplib sexplib
+  propagatedBuildInputs = [ cmdliner re uri fieldslib_p4 sexplib sexplib
                             conduit stringext base64 magic-mime ounit async
                             async_ssl lwt ];
 
diff --git a/pkgs/development/ocaml-modules/core/default.nix b/pkgs/development/ocaml-modules/core/default.nix
index 8110711a934..e52b41526ac 100644
--- a/pkgs/development/ocaml-modules/core/default.nix
+++ b/pkgs/development/ocaml-modules/core/default.nix
@@ -1,6 +1,6 @@
 {stdenv, buildOcaml, fetchurl, type_conv,
  core_kernel, bin_prot, comparelib, custom_printf, enumerate,
- fieldslib, herelib, pa_bench, pa_test, pa_ounit,
+ fieldslib_p4, herelib, pa_bench, pa_test, pa_ounit,
  pipebang, sexplib, typerep_p4, variantslib}:
 
 buildOcaml rec {
@@ -18,7 +18,7 @@ buildOcaml rec {
 
   buildInputs = [ pa_bench pa_test pa_ounit ];
   propagatedBuildInputs = [ type_conv core_kernel bin_prot comparelib
-                            custom_printf enumerate fieldslib herelib
+                            custom_printf enumerate fieldslib_p4 herelib
                             pipebang sexplib typerep_p4 variantslib ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/core_extended/default.nix b/pkgs/development/ocaml-modules/core_extended/default.nix
index f311aae3d30..e263d8d2c1b 100644
--- a/pkgs/development/ocaml-modules/core_extended/default.nix
+++ b/pkgs/development/ocaml-modules/core_extended/default.nix
@@ -1,5 +1,5 @@
 {stdenv, buildOcaml, fetchurl, bin_prot, comparelib, core, custom_printf,
- fieldslib, pa_bench, pa_ounit, pipebang, pa_test, textutils, re2, sexplib}:
+ fieldslib_p4, pa_bench, pa_ounit, pipebang, pa_test, textutils, re2, sexplib}:
 
 buildOcaml rec {
   name = "core_extended";
@@ -14,7 +14,7 @@ buildOcaml rec {
 
   hasSharedObjects = true;
   buildInputs = [ pa_bench pa_test pa_ounit ];
-  propagatedBuildInputs = [bin_prot comparelib core custom_printf fieldslib
+  propagatedBuildInputs = [bin_prot comparelib core custom_printf fieldslib_p4
                            pipebang textutils re2 sexplib ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/core_kernel/default.nix b/pkgs/development/ocaml-modules/core_kernel/default.nix
index 9be55061b00..9be9f578026 100644
--- a/pkgs/development/ocaml-modules/core_kernel/default.nix
+++ b/pkgs/development/ocaml-modules/core_kernel/default.nix
@@ -1,6 +1,6 @@
 {stdenv, buildOcaml, fetchurl, type_conv,
  bin_prot, comparelib, custom_printf, enumerate,
- fieldslib, herelib, pa_bench, pa_test, pa_ounit,
+ fieldslib_p4, herelib, pa_bench, pa_test, pa_ounit,
  pipebang, sexplib, typerep_p4, variantslib}:
 
 buildOcaml rec {
@@ -18,7 +18,7 @@ buildOcaml rec {
 
   buildInputs = [ pa_test pa_ounit ];
   propagatedBuildInputs = [ type_conv pa_bench bin_prot comparelib custom_printf
-                            enumerate fieldslib herelib pipebang sexplib
+                            enumerate fieldslib_p4 herelib pipebang sexplib
                             typerep_p4 variantslib ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/janestreet/fieldslib.nix b/pkgs/development/ocaml-modules/janestreet/fieldslib.nix
new file mode 100644
index 00000000000..8823a0c8054
--- /dev/null
+++ b/pkgs/development/ocaml-modules/janestreet/fieldslib.nix
@@ -0,0 +1,19 @@
+{ stdenv, type_conv, buildOcamlJane }:
+
+buildOcamlJane rec {
+  name = "fieldslib";
+  version = "113.33.03";
+
+  minimumSupportedOcamlVersion = "4.02";
+
+  hash = "0mkbix32f8sq32q81hb10z2q31bw5f431jxv0jafbdrif0vr6xqd";
+
+  propagatedBuildInputs = [ type_conv ];
+
+  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.maurer maintainers.vbgl ];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 7bb00176770..87ebf949bd3 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5202,7 +5202,7 @@ in
 
     faillib = callPackage ../development/ocaml-modules/faillib { };
 
-    fieldslib = callPackage ../development/ocaml-modules/fieldslib { };
+    fieldslib_p4 = callPackage ../development/ocaml-modules/fieldslib { };
 
     fileutils = callPackage ../development/ocaml-modules/fileutils { };
 
@@ -5558,7 +5558,11 @@ in
 
     ppx_jane = callPackage ../development/ocaml-modules/janestreet/ppx-jane.nix {};
 
+
+    # Core sublibs
     typerep = callPackage ../development/ocaml-modules/janestreet/typerep.nix {};
+
+    fieldslib = callPackage ../development/ocaml-modules/janestreet/fieldslib.nix {};
   };
 
   ocamlPackages = recurseIntoAttrs ocamlPackages_4_01_0;