diff --git a/pkgs/development/ocaml-modules/async_extra/default.nix b/pkgs/development/ocaml-modules/async_extra/default.nix
index af9407cd9c14..2a6c74f93a78 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_p4, core, custom_printf, fieldslib_p4, herelib, pa_ounit,
+ bin_prot_p4, core_p4, custom_printf, fieldslib_p4, herelib, pa_ounit,
  pipebang, pa_test, sexplib_p4}:
 
 buildOcaml rec {
@@ -14,7 +14,7 @@ buildOcaml rec {
   };
 
   buildInputs = [ pa_test pa_ounit ];
-  propagatedBuildInputs = [ async_kernel async_unix core bin_prot_p4 custom_printf
+  propagatedBuildInputs = [ async_kernel async_unix core_p4 bin_prot_p4 custom_printf
                             fieldslib_p4 herelib pipebang sexplib_p4 ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/async_find/default.nix b/pkgs/development/ocaml-modules/async_find/default.nix
index ed07a03753e7..82b9f83317a0 100644
--- a/pkgs/development/ocaml-modules/async_find/default.nix
+++ b/pkgs/development/ocaml-modules/async_find/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, async, core, sexplib_p4}:
+{stdenv, buildOcaml, fetchurl, async, core_p4, sexplib_p4}:
 
 buildOcaml rec {
   name = "async_find";
@@ -11,7 +11,7 @@ buildOcaml rec {
     sha256 = "4e3fda72f50174f05d96a5a09323f236c041b1a685890c155822956f3deb8803";
   };
 
-  propagatedBuildInputs = [ async core sexplib_p4 ];
+  propagatedBuildInputs = [ async core_p4 sexplib_p4 ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async_find;
diff --git a/pkgs/development/ocaml-modules/async_shell/default.nix b/pkgs/development/ocaml-modules/async_shell/default.nix
index 75755833a5f5..b8ca9097a48e 100644
--- a/pkgs/development/ocaml-modules/async_shell/default.nix
+++ b/pkgs/development/ocaml-modules/async_shell/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, async, core, core_extended}:
+{stdenv, buildOcaml, fetchurl, async, core_p4, core_extended}:
 
 buildOcaml rec {
   name = "async_shell";
@@ -11,7 +11,7 @@ buildOcaml rec {
     sha256 = "0b4497bea9124c5a665ee58fb0a73c5cbf2f757479df902e6870627196e6c105";
   };
 
-  propagatedBuildInputs = [ async core core_extended ];
+  propagatedBuildInputs = [ async core_p4 core_extended ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async_shell;
diff --git a/pkgs/development/ocaml-modules/async_ssl/default.nix b/pkgs/development/ocaml-modules/async_ssl/default.nix
index 52148c9d707d..8e0286e725da 100644
--- a/pkgs/development/ocaml-modules/async_ssl/default.nix
+++ b/pkgs/development/ocaml-modules/async_ssl/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, async, comparelib, core, ctypes, openssl,
+{stdenv, buildOcaml, fetchurl, async, comparelib, core_p4, ctypes, openssl,
  fieldslib_p4, herelib, pa_bench, pa_ounit, pipebang, pa_test, sexplib_p4}:
 
 buildOcaml rec {
@@ -13,7 +13,7 @@ buildOcaml rec {
   };
 
   buildInputs = [ pa_bench pa_test ];
-  propagatedBuildInputs = [ ctypes async comparelib core fieldslib_p4 pa_ounit
+  propagatedBuildInputs = [ ctypes async comparelib core_p4 fieldslib_p4 pa_ounit
                             herelib pipebang sexplib_p4 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 c3c18d560dd8..545f7efd85a7 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_p4, comparelib, core, fieldslib_p4, herelib, pa_ounit,
+ bin_prot_p4, comparelib, core_p4, fieldslib_p4, herelib, pa_ounit,
  pipebang, pa_test, sexplib_p4}:
 
 buildOcaml rec {
@@ -15,7 +15,7 @@ buildOcaml rec {
 
   hasSharedObjects = true;
   buildInputs = [ pa_ounit ];
-  propagatedBuildInputs = [ async_kernel core bin_prot_p4 comparelib
+  propagatedBuildInputs = [ async_kernel core_p4 bin_prot_p4 comparelib
                             fieldslib_p4 herelib pipebang pa_test sexplib_p4 ];
 
    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 78ac00f81831..e53c46894482 100644
--- a/pkgs/development/ocaml-modules/core_extended/default.nix
+++ b/pkgs/development/ocaml-modules/core_extended/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, bin_prot_p4, comparelib, core, custom_printf,
+{stdenv, buildOcaml, fetchurl, bin_prot_p4, comparelib, core_p4, custom_printf,
  fieldslib_p4, pa_bench, pa_ounit, pipebang, pa_test, textutils, re2, sexplib_p4}:
 
 buildOcaml rec {
@@ -14,7 +14,7 @@ buildOcaml rec {
 
   hasSharedObjects = true;
   buildInputs = [ pa_bench pa_test pa_ounit ];
-  propagatedBuildInputs = [bin_prot_p4 comparelib core custom_printf fieldslib_p4
+  propagatedBuildInputs = [bin_prot_p4 comparelib core_p4 custom_printf fieldslib_p4
                            pipebang textutils re2 sexplib_p4 ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/janestreet/core.nix b/pkgs/development/ocaml-modules/janestreet/core.nix
new file mode 100644
index 000000000000..05ea4d5d566b
--- /dev/null
+++ b/pkgs/development/ocaml-modules/janestreet/core.nix
@@ -0,0 +1,20 @@
+{stdenv, buildOcamlJane, fetchurl,
+ core_kernel,
+ bin_prot, fieldslib, sexplib, typerep, variantslib,
+ ppx_assert, ppx_bench, ppx_driver, ppx_expect, ppx_inline_test, ppx_jane,
+ ocaml_oasis, opam, js_build_tools}:
+
+buildOcamlJane rec {
+  name = "core";
+  hash = "0nz6d5glgymbpchvcpw77yis9jgi2bll32knzy9vx99wn83zdrmd";
+  propagatedBuildInputs =
+    [ core_kernel bin_prot fieldslib sexplib typerep variantslib
+      ppx_assert ppx_bench ppx_driver ppx_expect ppx_inline_test ppx_jane ];
+
+  meta = with stdenv.lib; {
+    homepage = https://github.com/janestreet/core;
+    description = "Jane Street Capital's standard library overlay";
+    license = licenses.asl20;
+    maintainers = [ maintainers.maurer maintainers.ericbmerritt ];
+  };
+}
diff --git a/pkgs/development/ocaml-modules/re2/default.nix b/pkgs/development/ocaml-modules/re2/default.nix
index d802d3fd44c7..9b26c4040959 100644
--- a/pkgs/development/ocaml-modules/re2/default.nix
+++ b/pkgs/development/ocaml-modules/re2/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, ocaml, core, pa_ounit, pa_test,
+{stdenv, buildOcaml, fetchurl, ocaml, core_p4, pa_ounit, pa_test,
  bin_prot_p4, comparelib, sexplib_p4, rsync}:
 
 buildOcaml rec {
@@ -16,7 +16,7 @@ buildOcaml rec {
             else null;
 
   buildInputs = [ pa_ounit pa_test rsync ];
-  propagatedBuildInputs = [ core bin_prot_p4 comparelib sexplib_p4 ];
+  propagatedBuildInputs = [ core_p4 bin_prot_p4 comparelib sexplib_p4 ];
 
   hasSharedObjects = true;
 
diff --git a/pkgs/development/ocaml-modules/textutils/default.nix b/pkgs/development/ocaml-modules/textutils/default.nix
index d3bb995769e9..6f35b9702280 100644
--- a/pkgs/development/ocaml-modules/textutils/default.nix
+++ b/pkgs/development/ocaml-modules/textutils/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, core, pa_ounit, pa_test, sexplib_p4}:
+{stdenv, buildOcaml, fetchurl, core_p4, pa_ounit, pa_test, sexplib_p4}:
 
 buildOcaml rec {
   name = "textutils";
@@ -12,7 +12,7 @@ buildOcaml rec {
   };
 
   buildInputs = [ pa_test ];
-  propagatedBuildInputs = [ core pa_ounit sexplib_p4 ];
+  propagatedBuildInputs = [ core_p4 pa_ounit sexplib_p4 ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/textutils;
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 86b302ca6794..93ccbe122387 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5305,7 +5305,7 @@ in
 
     core_kernel_p4 = callPackage ../development/ocaml-modules/core_kernel { };
 
-    core = callPackage ../development/ocaml-modules/core { };
+    core_p4 = callPackage ../development/ocaml-modules/core { };
 
     ocaml_cryptgps = callPackage ../development/ocaml-modules/cryptgps { };
 
@@ -5571,6 +5571,8 @@ in
     bin_prot = callPackage ../development/ocaml-modules/janestreet/bin_prot.nix {};
 
     core_kernel = callPackage ../development/ocaml-modules/janestreet/core_kernel.nix {};
+
+    core = callPackage ../development/ocaml-modules/janestreet/core.nix {};
   };
 
   ocamlPackages = recurseIntoAttrs ocamlPackages_4_01_0;