diff --git a/pkgs/development/ocaml-modules/cryptokit/default.nix b/pkgs/development/ocaml-modules/cryptokit/default.nix
index 461e2b88708..9ecd6dae294 100644
--- a/pkgs/development/ocaml-modules/cryptokit/default.nix
+++ b/pkgs/development/ocaml-modules/cryptokit/default.nix
@@ -1,17 +1,32 @@
-{ stdenv, fetchurl, zlib, ocaml, findlib, ocamlbuild, ncurses }:
+{ stdenv, fetchurl, zlib, ocaml, findlib, ocamlbuild, zarith, ncurses }:
 
 assert stdenv.lib.versionAtLeast ocaml.version "3.12";
 
-stdenv.mkDerivation rec {
-  name = "cryptokit-${version}";
-  version = "1.10";
-
-  src = fetchurl {
+let param =
+  if stdenv.lib.versionAtLeast ocaml.version "4.02"
+  then {
+    version = "1.11";
+    url = http://forge.ocamlcore.org/frs/download.php/1618/cryptokit-1.11.tar.gz;
+    sha256 = "1c1vn15lf2b5a8nfa2v2brxm7bwby540nf6q0vkndgkq5qcw96j8";
+    inherit zarith;
+  } else {
+    version = "1.10";
     url = http://forge.ocamlcore.org/frs/download.php/1493/cryptokit-1.10.tar.gz;
     sha256 = "1k2f2ixm7jcsgrzn9lz1hm9qqgq71lk9lxy3v3cwsd8xdrj3jrnv";
+    zarith = null;
+  };
+in
+
+stdenv.mkDerivation rec {
+  name = "cryptokit-${version}";
+  inherit (param) version;
+
+  src = fetchurl {
+    inherit (param) url sha256;
   };
 
   buildInputs = [ zlib ocaml findlib ocamlbuild ncurses ];
+  propagatedBuildInputs = [ param.zarith ];
 
   buildFlags = "setup.data build";
 
diff --git a/pkgs/development/ocaml-modules/zarith/default.nix b/pkgs/development/ocaml-modules/zarith/default.nix
index 458ed1683e0..09cefdfbb69 100644
--- a/pkgs/development/ocaml-modules/zarith/default.nix
+++ b/pkgs/development/ocaml-modules/zarith/default.nix
@@ -2,14 +2,26 @@
 
 assert stdenv.lib.versionAtLeast ocaml.version "3.12.1";
 
-stdenv.mkDerivation rec {
-  name = "zarith-${version}";
-  version = "1.3";
-
-  src = fetchurl {
+let param =
+  if stdenv.lib.versionAtLeast ocaml.version "4.02"
+  then {
+    version = "1.4.1";
+    url = http://forge.ocamlcore.org/frs/download.php/1574/zarith-1.4.1.tgz;
+    sha256 = "0l36hzmfbvdai2kcgynh13vfdim5x2grnaw61fxqalyjm90c3di3";
+  } else {
+    version = "1.3";
     url = http://forge.ocamlcore.org/frs/download.php/1471/zarith-1.3.tgz;
     sha256 = "1mx3nxcn5h33qhx4gbg0hgvvydwlwdvdhqcnvfwnmf9jy3b8frll";
   };
+in
+
+stdenv.mkDerivation rec {
+  name = "zarith-${version}";
+  inherit (param) version;
+
+  src = fetchurl {
+    inherit (param) url sha256;
+  };
 
   buildInputs = [ ocaml findlib pkgconfig perl ];
   propagatedBuildInputs = [ gmp ];