diff --git a/tox.ini b/tox.ini
index a6c270a..0d4ba8b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,11 +1,13 @@
 [tox:tox]
-envlist = py38,py39,py310,py311,py312,docs,style
+envlist = py38,py39,py310,py311,py312,py-radicale-xandikos,docs,style
 requires =
     tox>=4
 [testenv]
 usedevelop = true
 extras = test
-deps = radicale
+deps =
+    radicale: radicale
+    xandikos: xandikos
 commands =
     coverage: coverage run -m pytest []
     !coverage: pytest []