diff --git a/pkgs/development/ocaml-modules/angstrom/default.nix b/pkgs/development/ocaml-modules/angstrom/default.nix
index fadb55907bf..4f968ce6c09 100644
--- a/pkgs/development/ocaml-modules/angstrom/default.nix
+++ b/pkgs/development/ocaml-modules/angstrom/default.nix
@@ -1,14 +1,25 @@
 { stdenv, fetchFromGitHub, ocaml, ocamlbuild, cstruct, result, findlib, ocaml_oasis }:
 
+let param =
+  if stdenv.lib.versionAtLeast ocaml.version "4.03"
+  then {
+    version = "0.5.1";
+    sha256 = "0rm79xyszy9aqvflcc13y9xiya82z31fzmr3b3hx91pmqviymhgc";
+  } else {
+    version = "0.4.0";
+    sha256 = "019s3jwhnswa914bgj1fa6q67k0bl2ahqdaqfnavcbyii8763kh2";
+  };
+in
+
 stdenv.mkDerivation rec {
-  version = "0.4.0";
+  inherit (param) version;
   name = "ocaml-angstrom-${version}";
 
   src = fetchFromGitHub {
     owner  = "inhabitedtype";
     repo   = "angstrom";
     rev    = "${version}";
-    sha256 = "019s3jwhnswa914bgj1fa6q67k0bl2ahqdaqfnavcbyii8763kh2";
+    inherit (param) sha256;
   };
 
   createFindlibDestdir = true;