diff -r 527eba3013ea -r 8caec25f5d8f mercurial/configitems.py
--- a/mercurial/configitems.py	Thu Dec 12 09:59:03 2019 -0800
+++ b/mercurial/configitems.py	Wed Dec 11 19:42:05 2019 -0800
@@ -228,6 +228,9 @@
     b'commands', b'grep.all-files', default=False, experimental=True,
 )
 coreconfigitem(
+    b'commands', b'merge.require-rev', default=False,
+)
+coreconfigitem(
     b'commands', b'push.require-revs', default=False,
 )
 coreconfigitem(