--- a/mercurial/shelve.py	Wed Jul 15 11:38:54 2020 +0200
+++ b/mercurial/shelve.py	Fri Jul 17 09:20:48 2020 +0200
@@ -162,7 +162,7 @@
         repo = self.repo.unfiltered()
 
         outgoing = discovery.outgoing(
-            repo, missingroots=bases, missingheads=[node]
+            repo, missingroots=bases, ancestorsof=[node]
         )
         cg = changegroup.makechangegroup(repo, outgoing, cgversion, b'shelve')