diff --git a/cdl/utils/conf.py b/cdl/utils/conf.py
index 60dfc5d5..9d20b05e 100644
--- a/cdl/utils/conf.py
+++ b/cdl/utils/conf.py
@@ -4,6 +4,8 @@
 DataLab Configuration utilities
 """
 
+from __future__ import annotations
+
 import os
 import os.path as osp