diff --git a/pkgs/development/python-modules/channels/default.nix b/pkgs/development/python-modules/channels/default.nix
index d027c194675b..e4c8658f59bf 100644
--- a/pkgs/development/python-modules/channels/default.nix
+++ b/pkgs/development/python-modules/channels/default.nix
@@ -32,6 +32,10 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
+  pytestFlagsArray = [
+    "--asyncio-mode=legacy"
+  ];
+
   pythonImportsCheck = [ "channels" ];
 
   meta = with lib; {