diff --git a/pkgs/development/python-modules/python-pskc/default.nix b/pkgs/development/python-modules/python-pskc/default.nix
index e6a5b308a1a8..b6a63e78047f 100644
--- a/pkgs/development/python-modules/python-pskc/default.nix
+++ b/pkgs/development/python-modules/python-pskc/default.nix
@@ -10,18 +10,19 @@
   python-dateutil,
   setuptools,
   signxml,
+  stdenv,
 }:
 
 buildPythonPackage rec {
   pname = "python-pskc";
-  version = "1.4";
+  version = "1.4-unstable-2026-07-18";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "arthurdejong";
     repo = "python-pskc";
-    tag = version;
-    hash = "sha256-WBpS0EJA4arAn7O47ZHq3sBOd9D4tjYZKIi24xX5Hvs=";
+    rev = "6bcd0274db24467f7c9c410b31461228f70d6620";
+    hash = "sha256-0Pf803akJdTTCeMYC0/CwZNMySYQReFNbt69nl24AII=";
   };
 
   build-system = [
@@ -49,6 +50,16 @@ buildPythonPackage rec {
     export TZ=Europe/Amsterdam
   '';
 
+  disabledTestPaths = lib.optionals stdenv.hostPlatform.isDarwin [
+    # Assert difference between tzinfo=tzutc() and tzinfo=tzlocal()
+    "tests/test_draft_ietf_keyprov_pskc_02.doctest::test_draft_ietf_keyprov_pskc_02.doctest"
+    "tests/test_draft_keyprov.doctest::test_draft_keyprov.doctest"
+    "tests/test_feitian.doctest::test_feitian.doctest"
+    "tests/test_misc.doctest::test_misc.doctest"
+    "tests/test_rfc6030.doctest::test_rfc6030.doctest"
+    "tests/test_yubico.doctest::test_yubico.doctest"
+  ];
+
   pythonImportsCheck = [ "pskc" ];
 
   meta = {