diff --git a/pkgs/development/python-modules/pyotgw/default.nix b/pkgs/development/python-modules/pyotgw/default.nix
index ff519920ad66..c0f24aa3dc6d 100644
--- a/pkgs/development/python-modules/pyotgw/default.nix
+++ b/pkgs/development/python-modules/pyotgw/default.nix
@@ -30,10 +30,6 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
-  pytestFlagsArray = [
-    "--asyncio-mode=legacy"
-  ];
-
   pythonImportsCheck = [
     "pyotgw"
   ];