diff --git a/pkgs/development/python-modules/price-parser/default.nix b/pkgs/development/python-modules/price-parser/default.nix
index c2baaced3afb..0eb2a7a68eaf 100644
--- a/pkgs/development/python-modules/price-parser/default.nix
+++ b/pkgs/development/python-modules/price-parser/default.nix
@@ -4,14 +4,14 @@
   fetchFromGitHub,
   pytestCheckHook,
   setuptools,
-  pytest-cov,
+  pytest-cov-stub,
   attrs,
 }:
 
 buildPythonPackage rec {
   pname = "price-parser";
   version = "0.4.0";
-  format = "setuptools";
+  pyproject = true;
 
   src = fetchFromGitHub {
     owner = "scrapinghub";
@@ -20,11 +20,13 @@ buildPythonPackage rec {
     hash = "sha256-9f/+Yw94SVvg9fl9zYR9YEMwAgKHwySG5cysPMomnA0=";
   };
 
+  build-system = [ setuptools ];
+
   dependencies = [ attrs ];
 
   nativeCheckInputs = [
     pytestCheckHook
-    pytest-cov
+    pytest-cov-stub
   ];
 
   pythonImportsCheck = [ "price_parser" ];
diff --git a/pkgs/development/python-modules/pyppeteer-ng/default.nix b/pkgs/development/python-modules/pyppeteer-ng/default.nix
index 8894038470e9..0fd6e8acf27c 100644
--- a/pkgs/development/python-modules/pyppeteer-ng/default.nix
+++ b/pkgs/development/python-modules/pyppeteer-ng/default.nix
@@ -21,7 +21,7 @@
   pyee,
   pylint,
   pytest,
-  pytest-cov,
+  pytest-cov-stub,
   pytest-timeout,
   pytest-xdist,
   pytestCheckHook,
@@ -43,8 +43,6 @@ buildPythonPackage rec {
   version = "2.0.0rc10";
   pyproject = true;
 
-  disabled = pythonOlder "3.8";
-
   src = fetchFromGitHub {
     owner = "dgtlmoon";
     repo = "pyppeteer-ng";
@@ -96,7 +94,7 @@ buildPythonPackage rec {
     pydocstyle
     pylint
     pytest
-    pytest-cov
+    pytest-cov-stub
     pytest-timeout
     pytest-xdist
     readme-renderer