diff --git a/pkgs/development/python-modules/pylint-flask/default.nix b/pkgs/development/python-modules/pylint-flask/default.nix
index 4a26e256d803..0928e0bd07e1 100644
--- a/pkgs/development/python-modules/pylint-flask/default.nix
+++ b/pkgs/development/python-modules/pylint-flask/default.nix
@@ -1,37 +1,50 @@
-{ buildPythonPackage
+{ lib
+, astroid
+, buildPythonPackage
 , fetchPypi
-, isPy3k
-, lib
-
-# pythonPackages
+, pylint
 , pylint-plugin-utils
+, pythonOlder
+, setuptools
 }:
 
 buildPythonPackage rec {
   pname = "pylint-flask";
   version = "0.6";
-  format = "setuptools";
-  disabled = !isPy3k;
+  pyproject = true;
+
+  disabled = pythonOlder "3.7";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "05qmwgkpvaa5k05abqjxfbrfk3wpdqb8ph690z7bzxvb47i7vngl";
+    hash = "sha256-9Nl94iFr97/OB8nAixZul4/p8nJd4qUKmEWpfefjFRc=";
   };
 
+  nativeBuildInputs = [
+    setuptools
+  ];
+
+  buildInputs = [
+    pylint
+  ];
+
   propagatedBuildInputs = [
+    astroid
     pylint-plugin-utils
   ];
 
   # Tests require a very old version of pylint
-  #   also tests are only available at GitHub, with an old release tag
+  # also tests are only available at GitHub, with an old release tag
   doCheck = false;
 
+  pythonImportsCheck = [
+    "pylint_flask"
+  ];
+
   meta = with lib; {
     description = "A Pylint plugin to analyze Flask applications";
     homepage = "https://github.com/jschaf/pylint-flask";
-    license = licenses.gpl2;
-    maintainers = with maintainers; [
-      kamadorueda
-    ];
+    license = licenses.gpl2Only;
+    maintainers = with maintainers; [ kamadorueda ];
   };
 }
diff --git a/pkgs/development/python-modules/pylint-plugin-utils/default.nix b/pkgs/development/python-modules/pylint-plugin-utils/default.nix
index cdc29eb19621..83315aed22a0 100644
--- a/pkgs/development/python-modules/pylint-plugin-utils/default.nix
+++ b/pkgs/development/python-modules/pylint-plugin-utils/default.nix
@@ -39,9 +39,6 @@ buildPythonPackage rec {
     "pylint_plugin_utils"
   ];
 
-  # https://github.com/PyCQA/pylint-plugin-utils/issues/26
-  doCheck = false;
-
   meta = with lib; {
     description = "Utilities and helpers for writing Pylint plugins";
     homepage = "https://github.com/PyCQA/pylint-plugin-utils";
diff --git a/pkgs/development/python-modules/requirements-detector/default.nix b/pkgs/development/python-modules/requirements-detector/default.nix
index bc6054ffad1b..e679937dbd4c 100644
--- a/pkgs/development/python-modules/requirements-detector/default.nix
+++ b/pkgs/development/python-modules/requirements-detector/default.nix
@@ -7,25 +7,31 @@
 , semver
 , pytestCheckHook
 , pythonOlder
+, pythonRelaxDepsHook
 , toml
 }:
 
 buildPythonPackage rec {
   pname = "requirements-detector";
   version = "1.2.2";
-  format = "pyproject";
+  pyproject = true;
 
   disabled = pythonOlder "3.7";
 
   src = fetchFromGitHub {
     owner = "landscapeio";
-    repo = pname;
+    repo = "requirements-detector";
     rev = "refs/tags/${version}";
     hash = "sha256-qmrHFQRypBJOI1N6W/Dtc5ss9JGqoPhFlbqrLHcb6vc=";
   };
 
+  pythonRelaxDeps = [
+    "astroid"
+  ];
+
   nativeBuildInputs = [
     poetry-core
+    pythonRelaxDepsHook
   ];
 
   propagatedBuildInputs = [