diff --git a/pkgs/development/python-modules/x690/default.nix b/pkgs/development/python-modules/x690/default.nix
new file mode 100644
index 000000000000..61ec38319a6b
--- /dev/null
+++ b/pkgs/development/python-modules/x690/default.nix
@@ -0,0 +1,53 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchFromGitHub,
+  setuptools,
+  t61codec,
+  pytest-cov-stub,
+  pytestCheckHook,
+}:
+
+buildPythonPackage rec {
+  pname = "x690";
+  version = "1.0.0";
+  pyproject = true;
+
+  src = fetchFromGitHub {
+    owner = "exhuma";
+    repo = "x690";
+    tag = "v${version}";
+    hash = "sha256-yU4FABlTAFoj87SJXDA+sVCJT3pCbYxpTXp7Ja2ltGE=";
+  };
+
+  build-system = [
+    setuptools
+  ];
+
+  pythonRelaxDeps = [
+    "t61codec"
+  ];
+
+  dependencies = [
+    t61codec
+  ];
+
+  pythonImportsCheck = [ "x690" ];
+
+  nativeCheckInputs = [
+    pytest-cov-stub
+    pytestCheckHook
+  ];
+
+  disabledTests = [
+    # AssertionError: "<UnknownType 99 b'abc' TypeClass.APPLICATION/TypeNature.CONSTRUCTED/3>" != "<UnknownType 99 b'abc' application/constructed/3>"
+    "test_repr"
+  ];
+
+  meta = {
+    description = "Pure Python X.690 implementation";
+    homepage = "https://github.com/exhuma/x690";
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ GaetanLepage ];
+  };
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index a59a89f7c4d8..eb7f4d9a94ca 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -19025,6 +19025,8 @@ self: super: with self; {
 
   x256 = callPackage ../development/python-modules/x256 { };
 
+  x690 = callPackage ../development/python-modules/x690 { };
+
   xapian = callPackage ../development/python-modules/xapian { inherit (pkgs) xapian; };
 
   xarray = callPackage ../development/python-modules/xarray { };