diff --git a/qlib/config.py b/qlib/config.py
index 2bd77feb8..878888a84 100644
--- a/qlib/config.py
+++ b/qlib/config.py
@@ -13,7 +13,7 @@ Two modes are supported
 
 import copy
 from pathlib import Path
-import re
+import re, os
 
 
 class Config: