diff --git a/pkgs/development/python-modules/cattrs/default.nix b/pkgs/development/python-modules/cattrs/default.nix
index 7d3efc9fb3b3..94a357df98be 100644
--- a/pkgs/development/python-modules/cattrs/default.nix
+++ b/pkgs/development/python-modules/cattrs/default.nix
@@ -7,6 +7,7 @@
 , motor
 , msgpack
 , poetry-core
+, pytest-xdist
 , pytestCheckHook
 , pythonOlder
 , pyyaml
@@ -44,12 +45,17 @@ buildPythonPackage rec {
     immutables
     motor
     msgpack
+    pytest-xdist
     pytestCheckHook
     pyyaml
     tomlkit
     ujson
   ];
 
+  pytestFlagsArray = [
+    "--numprocesses $NIX_BUILD_CORES"
+  ];
+
   postPatch = ''
     substituteInPlace pyproject.toml \
       --replace "-l --benchmark-sort=fullname --benchmark-warmup=true --benchmark-warmup-iterations=5  --benchmark-group-by=fullname" "" \