diff --git a/pkgs/development/ocaml-modules/janestreet/ppx_let-113_33_00.nix b/pkgs/development/ocaml-modules/janestreet/ppx_let-113_33_00.nix
new file mode 100644
index 00000000000..b5f0bd4c932
--- /dev/null
+++ b/pkgs/development/ocaml-modules/janestreet/ppx_let-113_33_00.nix
@@ -0,0 +1,21 @@
+{ stdenv, fetchurl, ocaml, findlib, ocamlbuild, opam, topkg
+, ppx_driver
+}:
+
+stdenv.mkDerivation {
+  name = "ocaml${ocaml.version}-ppx_let-113.33.00+4.03";
+  src = fetchurl {
+    url = http://ocaml.janestreet.com/ocaml-core/113.33/files/ppx_let-113.33.00+4.03.tar.gz;
+    sha256 = "012yzayknm9qv8ap9rbwf4fwnmx935mfy7c75ifagbnfl4lh7dmp";
+  };
+
+  buildInputs = [ ocaml findlib ocamlbuild opam ];
+  propagatedBuildInputs = [ ppx_driver ];
+
+  inherit (topkg) installPhase;
+
+  meta = {
+    license = stdenv.lib.licenses.asl20;
+    inherit (ocaml.meta) platforms;
+  };
+}
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index 8cf09dc6ad3..d8659335d2e 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -615,7 +615,10 @@ let
       then callPackage ../development/ocaml-modules/janestreet/ppx_fields_conv-113_33_00.nix {}
       else callPackage ../development/ocaml-modules/janestreet/ppx-fields-conv.nix {};
 
-    ppx_let = callPackage ../development/ocaml-modules/janestreet/ppx-let.nix {};
+    ppx_let =
+      if lib.versionOlder "4.03" ocaml.version
+      then callPackage ../development/ocaml-modules/janestreet/ppx_let-113_33_00.nix {}
+      else callPackage ../development/ocaml-modules/janestreet/ppx-let.nix {};
 
     ppx_pipebang = callPackage ../development/ocaml-modules/janestreet/ppx-pipebang.nix {};