diff --git a/pkgs/development/python-modules/pycardano/default.nix b/pkgs/development/python-modules/pycardano/default.nix
index e5f164e9fe92..7b36de98ace2 100644
--- a/pkgs/development/python-modules/pycardano/default.nix
+++ b/pkgs/development/python-modules/pycardano/default.nix
@@ -25,7 +25,7 @@
 }:
 
 let
-  cose_0_9_dev8 = cose.overridePythonAttrs (old: rec {
+  cose_0_9_dev8 = (cose.override { inherit cbor2; }).overridePythonAttrs (old: rec {
     version = "0.9.dev8";
     src = (
       old.src.override {
@@ -38,14 +38,14 @@ let
 in
 buildPythonPackage rec {
   pname = "pycardano";
-  version = "0.12.3";
+  version = "0.14.0";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "Python-Cardano";
     repo = "pycardano";
     tag = "v${version}";
-    hash = "sha256-jxgskdQ7Us+utndUgFYK7G2IW/e5QbeXytOsxQfFiJI=";
+    hash = "sha256-W5N254tND7mI0oR82YhMFWn4zVVs3ygYOqXOBMO3sXY=";
   };
 
   build-system = [
@@ -88,5 +88,9 @@ buildPythonPackage rec {
     homepage = "https://github.com/Python-Cardano/pycardano";
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ t4ccer ];
+    # https://github.com/Python-Cardano/pycardano/blob/v0.13.2/Makefile#L26-L39
+    # cbor2 with C extensions fail tests due to differences in used sized vs unsized arrays
+    # more info: https://github.com/NixOS/nixpkgs/pull/402433#issuecomment-2916520286
+    broken = cbor2.withCExtensions; # consider overriding cbor2 with cbor2WithoutCExtensions
   };
 }