diff --git a/conf.py b/conf.py
index 0ab3786..8f8c773 100644
--- a/conf.py
+++ b/conf.py
@@ -17,7 +17,7 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 #
-# import os
+ import os
 # import sys
 # sys.path.insert(0, os.path.abspath('.'))
 
@@ -235,4 +235,4 @@
         'preamble' : r'''
         \usepackage{ctex}
         ''',
-    }
\ No newline at end of file
+    }