diff --git a/pkgs/development/ocaml-modules/lwt/default.nix b/pkgs/development/ocaml-modules/lwt/default.nix
index 4254b78287c5..20acb75d931a 100644
--- a/pkgs/development/ocaml-modules/lwt/default.nix
+++ b/pkgs/development/ocaml-modules/lwt/default.nix
@@ -1,7 +1,7 @@
-{stdenv, fetchgit, which, cryptopp, ocaml, findlib, ocaml_react, ocaml_ssl, libev, pkgconfig, ncurses, ocaml_oasis, ocaml_text, glib, camlp4}:
+{stdenv, fetchzip, which, cryptopp, ocaml, findlib, ocaml_react, ocaml_ssl, libev, pkgconfig, ncurses, ocaml_oasis, ocaml_text, glib, camlp4}:
 
 let
-  version = "2.4.5";
+  version = "2.4.6";
   inherit (stdenv.lib) optional getVersion versionAtLeast;
   ocaml_version = getVersion ocaml;
 in
@@ -11,17 +11,16 @@ stdenv.mkDerivation {
 
   name = "ocaml-lwt-${version}";
 
-  src = fetchgit {
-    url = git://github.com/ocsigen/lwt;
-    rev = "refs/tags/${version}";
-    sha256 = "2bbf4f216dd62eeb765a89413f3b2b6d417a9c289ca49d595bb4d7a0545e343e";
+  src = fetchzip {
+    url = "https://github.com/ocsigen/lwt/archive/${version}.tar.gz";
+    sha256 = "0idci0zadpb8hmblszsrvg6yf36w5a9y6rsdwjc3jww71dgrw5d9";
   };
 
   buildInputs = [ocaml_oasis pkgconfig which cryptopp ocaml findlib glib libev ncurses camlp4];
 
   propagatedBuildInputs = [ ocaml_react ocaml_ssl ocaml_text ];
 
-  configureFlags = [ "--enable-react" "--enable-glib" "--enable-ssl" "--enable-text" ]
+  configureFlags = [ "--enable-react" "--enable-glib" "--enable-ssl" "--enable-text" "--disable-ppx" ]
   ++ optional (versionAtLeast ocaml_version "4.0" && ! versionAtLeast ocaml_version "4.02") "--enable-toplevel";
 
   createFindlibDestdir = true;