--- a/hgext/acl.py	Mon Jul 03 02:52:40 2017 +0900
+++ b/hgext/acl.py	Sun Jul 02 23:10:33 2017 +0200
@@ -219,7 +219,7 @@
     default=None,
 )
 configitem('acl', 'sources',
-    default=['serve'],
+    default=lambda: ['serve'],
 )
 
 def _getusers(ui, group):