diff --git a/pytest.ini b/pytest.ini
index 3046dfd85..73d169601 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -1,5 +1,6 @@
 [pytest]
 usefixtures = chdir
 python_files=test_*.py __init__.py
+python_classes=
 addopts = --doctest-modules --assert=plain
 twisted = 1