diff --git a/pkgs/development/ocaml-modules/toml/default.nix b/pkgs/development/ocaml-modules/toml/default.nix
index b79d80016d9c..41c52985cf99 100644
--- a/pkgs/development/ocaml-modules/toml/default.nix
+++ b/pkgs/development/ocaml-modules/toml/default.nix
@@ -1,4 +1,4 @@
-{ lib, fetchFromGitHub, buildDunePackage
+{ lib, fetchFromGitHub, fetchpatch, buildDunePackage
 , iso8601, menhir
 }:
 
@@ -13,6 +13,12 @@ buildDunePackage rec {
     sha256 = "sha256-VEZQTFPwAGShCBGbKUiNOIY1zA/JdTpXU0ZIGNWopnQ=";
   };
 
+  # Ensure compatibility with menhir ≥ 20211215
+  patches = fetchpatch {
+    url = "https://github.com/ocaml-toml/To.ml/commit/41172b739dff43424a12f7c1f0f64939e3660648.patch";
+    sha256 = "sha256:1333xkmm9qp5m3pp4y5w17k6rvmb30v62qyra6rfk1km2v28hqqq";
+  };
+
   nativeBuildInputs = [ menhir ];
   propagatedBuildInputs = [ iso8601 ];