diff --git a/pkgs/development/python-modules/unifi-discovery/default.nix b/pkgs/development/python-modules/unifi-discovery/default.nix
index 5b1e86459867..68d28d0f4756 100644
--- a/pkgs/development/python-modules/unifi-discovery/default.nix
+++ b/pkgs/development/python-modules/unifi-discovery/default.nix
@@ -39,6 +39,10 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
+  pytestFlagsArray = [
+    "--asyncio-mode=legacy"
+  ];
+
   postPatch = ''
     substituteInPlace pyproject.toml \
       --replace "--cov=unifi_discovery --cov-report=term-missing:skip-covered" ""