diff --git a/pkgs/development/python-modules/ansible-lint/default.nix b/pkgs/development/python-modules/ansible-lint/default.nix
index a6381362b383..2fac5e8a021e 100644
--- a/pkgs/development/python-modules/ansible-lint/default.nix
+++ b/pkgs/development/python-modules/ansible-lint/default.nix
@@ -49,7 +49,7 @@ buildPythonPackage rec {
   ];
 
   pytestFlagsArray = [
-    "--numprocesses" "auto"
+    "--numprocesses" "$NIX_BUILD_CORES"
   ];
 
   preCheck = ''