diff --git a/pkgs/development/python-modules/terminado/default.nix b/pkgs/development/python-modules/terminado/default.nix
index 7773844c2feb..6b266e62ee74 100644
--- a/pkgs/development/python-modules/terminado/default.nix
+++ b/pkgs/development/python-modules/terminado/default.nix
@@ -34,6 +34,7 @@ buildPythonPackage rec {
     pytest-timeout
     pytestCheckHook
   ];
+  pytestFlags = [ "-Wignore::pytest.PytestUnraisableExceptionWarning" ];
 
   meta = with lib; {
     description = "Terminals served by Tornado websockets";