--- a/mercurial/configitems.py	Wed Oct 18 14:55:39 2017 -0700
+++ b/mercurial/configitems.py	Wed Oct 18 15:05:03 2017 -0700
@@ -181,6 +181,9 @@
 coreconfigitem('color', 'pagermode',
     default=dynamicdefault,
 )
+coreconfigitem('commands', 'show.aliasprefix',
+    default=list,
+)
 coreconfigitem('commands', 'status.relative',
     default=False,
 )