diff -r 083438d6f403 -r a51d345f1404 mercurial/upgrade_utils/actions.py
--- a/mercurial/upgrade_utils/actions.py	Wed Dec 16 12:39:15 2020 +0530
+++ b/mercurial/upgrade_utils/actions.py	Wed Dec 16 14:06:24 2020 +0530
@@ -526,7 +526,9 @@
     return list(ALL_OPTIMISATIONS)
 
 
-def determineactions(repo, format_upgrades, sourcereqs, destreqs):
+def determineactions(
+    repo, format_upgrades, optimizations, sourcereqs, destreqs
+):
     """Determine upgrade actions that will be performed.
 
     Given a list of improvements as returned by ``find_format_upgrades`` and
@@ -551,6 +553,8 @@
 
         newactions.append(d)
 
+    newactions.extend(o for o in sorted(optimizations) if o not in newactions)
+
     # FUTURE consider adding some optimizations here for certain transitions.
     # e.g. adding generaldelta could schedule parent redeltas.