diff --git a/pkgs/development/python-modules/pygls/default.nix b/pkgs/development/python-modules/pygls/default.nix
index d563fa27669..edd5d9bc310 100644
--- a/pkgs/development/python-modules/pygls/default.nix
+++ b/pkgs/development/python-modules/pygls/default.nix
@@ -1,30 +1,29 @@
-{ stdenv, buildPythonPackage, isPy3k, fetchFromGitHub
-, mock, pytest, pytest-asyncio
+{ lib
+, buildPythonPackage
+, isPy3k
+, fetchFromGitHub
+, mock
+, pytest-asyncio
+, pytestCheckHook
 }:
 
 buildPythonPackage rec {
   pname = "pygls";
-  version = "0.9.0";
+  version = "0.9.1";
   disabled = !isPy3k;
 
   src = fetchFromGitHub {
     owner = "openlawlibrary";
     repo = pname;
     rev = "v${version}";
-    sha256 = "1wfp4hjin1mb6nkzhpfh5v8q8rwvn9zh0mwwj4dlxkqx5lp272hl";
+    sha256 = "1v7x5598d6jg8ya0spqjma56y062rznwimsrp8nq6fkskqgfm0ds";
   };
 
-  postPatch = ''
-    substituteInPlace setup.py \
-      --replace "pytest==4.5.0" "pytest"
-  '';
+  checkInputs = [ mock pytest-asyncio pytestCheckHook ];
 
-  checkInputs = [ mock pytest pytest-asyncio ];
-  checkPhase = "pytest";
-
-  meta = with stdenv.lib; {
-    homepage = "https://github.com/openlawlibrary/pygls";
+  meta = with lib; {
     description = "Pythonic generic implementation of the Language Server Protocol";
+    homepage = "https://github.com/openlawlibrary/pygls";
     license = licenses.asl20;
     maintainers = with maintainers; [ metadark ];
   };