diff --git a/pkgs/development/ocaml-modules/csexp/default.nix b/pkgs/development/ocaml-modules/csexp/default.nix
index 26c064d6ff5..4bb83019dc5 100644
--- a/pkgs/development/ocaml-modules/csexp/default.nix
+++ b/pkgs/development/ocaml-modules/csexp/default.nix
@@ -2,7 +2,7 @@
 
 buildDunePackage rec {
   pname = "csexp";
-  version = "1.3.2";
+  version = "1.4.0";
 
   useDune2 = true;
 
@@ -10,7 +10,7 @@ buildDunePackage rec {
 
   src = fetchurl {
     url = "https://github.com/ocaml-dune/csexp/releases/download/${version}/csexp-${version}.tbz";
-    sha256 = "0jhwrxfjb0x31xj4g4b89fzw34sq19j0rq2hs2zyh1vz4xxl47zj";
+    sha256 = "sha256-jj1vyofxAqEm3ui3KioNFG8QQ5xHIY38FJ1Rvz7fNk4=";
   };
 
   propagatedBuildInputs = [ result ];