diff --git a/pkgs/development/ocaml-modules/topkg/default.nix b/pkgs/development/ocaml-modules/topkg/default.nix
index f343eed6b467..fa238a84b35c 100644
--- a/pkgs/development/ocaml-modules/topkg/default.nix
+++ b/pkgs/development/ocaml-modules/topkg/default.nix
@@ -1,5 +1,9 @@
 { stdenv, fetchurl, ocaml, findlib, ocamlbuild, result, opam }:
 
+if !stdenv.lib.versionAtLeast ocaml.version "4.01"
+then throw "topkg is not available for OCaml ${ocaml.version}"
+else
+
 stdenv.mkDerivation rec {
   name = "ocaml${ocaml.version}-topkg-${version}";
   version = "0.8.1";