diff --git a/radicale/tests/test_group.py b/radicale/tests/test_group.py
index 8b280fad..ef8808ad 100644
--- a/radicale/tests/test_group.py
+++ b/radicale/tests/test_group.py
@@ -21,6 +21,7 @@ Radicale tests related to group lookup.
 
 import logging
 import os
+import sys
 
 import pytest