diff --git a/pkgs/development/ocaml-modules/x509/default.nix b/pkgs/development/ocaml-modules/x509/default.nix
index 76076039518c..aca71e2dfc17 100644
--- a/pkgs/development/ocaml-modules/x509/default.nix
+++ b/pkgs/development/ocaml-modules/x509/default.nix
@@ -8,13 +8,13 @@ buildDunePackage rec {
   minimalOCamlVersion = "4.08";
 
   pname = "x509";
-  version = "0.16.4";
+  version = "0.16.5";
 
   duneVersion = "3";
 
   src = fetchurl {
     url = "https://github.com/mirleft/ocaml-x509/releases/download/v${version}/x509-${version}.tbz";
-    hash = "sha256-XegxhdASQK/I7Xd0gJSLumTGbCYFpWsjR7PlZSWqaVo=";
+    hash = "sha256-FJ4lpf6jf2GfsmkL7lwA8BydzzHTNfj/yqs5p1OMzZk=";
   };
 
   checkInputs = [ alcotest cstruct-unix ];