diff --git a/pkgs/development/python-modules/gridnet/default.nix b/pkgs/development/python-modules/gridnet/default.nix
index 6763a42291a6..6b89ae50b019 100644
--- a/pkgs/development/python-modules/gridnet/default.nix
+++ b/pkgs/development/python-modules/gridnet/default.nix
@@ -6,6 +6,7 @@
   fetchFromGitHub,
   poetry-core,
   pytest-asyncio,
+  pytest-cov-stub,
   pytestCheckHook,
   pythonOlder,
   yarl,
@@ -27,8 +28,7 @@ buildPythonPackage rec {
 
   postPatch = ''
     substituteInPlace pyproject.toml \
-      --replace "0.0.0" "${version}" \
-      --replace "--cov" ""
+      --replace "0.0.0" "${version}"
   '';
 
   nativeBuildInputs = [ poetry-core ];
@@ -41,6 +41,7 @@ buildPythonPackage rec {
   nativeCheckInputs = [
     aresponses
     pytest-asyncio
+    pytest-cov-stub
     pytestCheckHook
   ];