diff --git a/pkgs/development/ocaml-modules/ocsigen-toolkit/default.nix b/pkgs/development/ocaml-modules/ocsigen-toolkit/default.nix
index b5638229e0c4..d421c01610b4 100644
--- a/pkgs/development/ocaml-modules/ocsigen-toolkit/default.nix
+++ b/pkgs/development/ocaml-modules/ocsigen-toolkit/default.nix
@@ -5,7 +5,7 @@
 stdenv.mkDerivation rec {
  pname = "ocsigen-toolkit";
  name = "ocaml${ocaml.version}-${pname}-${version}";
- version = "3.3.4";
+ version = "4.1.0";
 
  propagatedBuildInputs = [ calendar js_of_ocaml-ppx_deriving_json eliom ];
  nativeBuildInputs = [ ocaml findlib opaline eliom ];
@@ -25,7 +25,7 @@ stdenv.mkDerivation rec {
     owner = "ocsigen";
     repo = pname;
     rev = version;
-    hash = "sha256-6ccu8WJxUwpR5YyB4j1jQPWba8GhQDxuw+IDHswQpSA=";
+    hash = "sha256-1kw2HANajHDdMmjuYNB79ZDqy2Ml02nc5s+cJzIoxQ8=";
   };
 
   meta = {