diff --git a/pkgs/development/ocaml-modules/janestreet/0.17.nix b/pkgs/development/ocaml-modules/janestreet/0.17.nix
index 404dfd614fbd..43d600469aeb 100644
--- a/pkgs/development/ocaml-modules/janestreet/0.17.nix
+++ b/pkgs/development/ocaml-modules/janestreet/0.17.nix
@@ -1,6 +1,7 @@
 {
   self,
   bash,
+  fetchpatch,
   fzf,
   lib,
   openssl,
@@ -498,6 +499,13 @@ with self;
       patchShebangs unix_pseudo_terminal/src/discover.sh
     '';
     doCheck = false; # command_validate_parsing.exe is not specified in test build deps
+
+    # Compatibility with OCaml 5.3
+    patches = lib.optional (lib.versionAtLeast ocaml.version "5.3") (fetchpatch {
+      url = "https://github.com/janestreet/core_unix/commit/ebce389ac68e098f542e34400e114ac992f415af.patch";
+      includes = [ "bigstring_unix/src/bigstring_unix_stubs.c" ];
+      hash = "sha256-FGg2zlyp3aZFu1VeFdm7pgSPiW0HAkLYgMGTj+tqju8=";
+    });
   };
 
   csvfields = janePackage {
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index d8649636dbb2..9bcc8ab5b821 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -793,7 +793,7 @@ let
       then import ../development/ocaml-modules/janestreet/0.17.nix
          {
            inherit self;
-           inherit (pkgs) bash fzf lib openssl zstd;
+           inherit (pkgs) bash fetchpatch fzf lib openssl zstd;
          }
       else if lib.versionOlder "4.13.1" ocaml.version
       then import ../development/ocaml-modules/janestreet/0.16.nix {