diff --git a/pkgs/development/python-modules/stm32loader/default.nix b/pkgs/development/python-modules/stm32loader/default.nix
index 55a86231aa70..00de51ea66f5 100644
--- a/pkgs/development/python-modules/stm32loader/default.nix
+++ b/pkgs/development/python-modules/stm32loader/default.nix
@@ -1,30 +1,53 @@
 { lib
 , buildPythonPackage
-, isPy27
 , fetchPypi
+
+# build-system
+, flit-core
+
+# dependenices
 , progress
 , pyserial
-, pytest
-, mock
+
+# optional-dependencies
+, intelhex
+
+# tests
+, pytestCheckHook
 }:
 
 buildPythonPackage rec {
   pname = "stm32loader";
-  version = "0.5.1";
-  format = "setuptools";
+  version = "0.7.1";
+  pyproject = true;
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "0135qzxlrivvkq6wgkw7shfz94n755qs2c1754p1hc2jk0nqayrg";
+    hash = "sha256-QTLSEjdJtDH4GCamnKHN5pEjW41rRtAMXxyZZMM5K3w=";
   };
 
-  propagatedBuildInputs = [ progress pyserial ];
+  nativeBuildInputs = [
+    flit-core
+  ];
 
-  nativeCheckInputs = [ pytest ] ++ lib.optional isPy27 mock;
+  propagatedBuildInputs = [
+    progress
+    pyserial
+  ];
 
-  checkPhase = ''
-    pytest --strict tests/unit
-  '';
+  passthru.optional-dependencies = {
+    hex = [
+      intelhex
+    ];
+  };
+
+  nativeCheckInputs = [
+    pytestCheckHook
+  ] ++ lib.flatten (lib.attrValues passthru.optional-dependencies);
+
+  pytestFlagsArray = [
+    "tests/unit"
+  ];
 
   meta = with lib; {
     description = "Flash firmware to STM32 microcontrollers in Python";