--- a/mercurial/configitems.py	Wed Jan 06 16:01:19 2021 +0530
+++ b/mercurial/configitems.py	Wed Jan 06 16:18:06 2021 +0530
@@ -1074,6 +1074,11 @@
 )
 coreconfigitem(
     b'experimental',
+    b'sharesafe-auto-upgrade-shares',
+    default=False,
+)
+coreconfigitem(
+    b'experimental',
     b'single-head-per-branch',
     default=False,
 )