diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -547,6 +547,9 @@
 coreconfigitem('experimental', 'evolution.report-instabilities',
     default=True,
 )
+coreconfigitem('experimental', 'evolution.stackaliases',
+    default=True,
+)
 coreconfigitem('experimental', 'evolution.track-operation',
     default=True,
 )