diff --git a/pkgs/development/python-modules/matrix-nio/default.nix b/pkgs/development/python-modules/matrix-nio/default.nix
index 724a1459b779..586f1ef96a1c 100644
--- a/pkgs/development/python-modules/matrix-nio/default.nix
+++ b/pkgs/development/python-modules/matrix-nio/default.nix
@@ -78,7 +78,10 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
-  pytestFlagsArray = [ "--benchmark-disable" ];
+  pytestFlagsArray = [
+    "--asyncio-mode=legacy"
+    "--benchmark-disable"
+  ];
 
   disabledTests = [
     # touches network