diff --git a/pytest.ini b/pytest.ini
index 117bd5517b19..0f7d1b252c45 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -7,6 +7,8 @@ python_files = test_*.py
 markers =
     backend: Set alternate Matplotlib backend temporarily.
     style: Set alternate Matplotlib style temporarily.
+    baseline_images: Compare output against a known reference
+    pytz: Tests that require pytz to be installed
 
 filterwarnings =
     error