diff --git a/pytest.ini b/pytest.ini
index e9fffce6..3693332d 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -9,6 +9,7 @@ python_functions = pytest_*
 
 # Turn warnings into errors.  Warnings are signs that something needs
 # attention, even if that means choosing to add an explicit ignore filter rule
-# for them.
+# for them.  Last matching filter wins.
 filterwarnings =
     error
+    ignore:SelectableGroups dict interface:DeprecationWarning:flake8