diff --git a/mercurial/upgrade.py b/mercurial/upgrade.py
--- a/mercurial/upgrade.py
+++ b/mercurial/upgrade.py
@@ -1274,6 +1274,17 @@
             ui.write((b'\n'))
         ui.write(b'\n')
 
+    def printoptimisations():
+        optimisations = [a for a in actions if a.type == optimisation]
+        optimisations.sort(key=lambda a: a.name)
+        if optimisations:
+            ui.write(_(b'optimisations: '))
+            write_labeled(
+                [a.name for a in optimisations],
+                "upgrade-repo.optimisation.performed",
+            )
+            ui.write(b'\n\n')
+
     def printupgradeactions():
         for a in actions:
             ui.write(b'%s\n   %s\n\n' % (a.name, a.upgrademessage))
@@ -1327,6 +1338,7 @@
         )
 
         printrequirements()
+        printoptimisations()
         printupgradeactions()
 
         unusedoptimize = [i for i in alloptimizations if i not in actions]
@@ -1345,6 +1357,7 @@
     # Else we're in the run=true case.
     ui.write(_(b'upgrade will perform the following actions:\n\n'))
     printrequirements()
+    printoptimisations()
     printupgradeactions()
 
     upgradeactions = [a.name for a in actions]
diff --git a/tests/test-upgrade-repo.t b/tests/test-upgrade-repo.t
--- a/tests/test-upgrade-repo.t
+++ b/tests/test-upgrade-repo.t
@@ -183,6 +183,8 @@
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
   
+  optimisations: re-delta-parent
+  
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
@@ -207,6 +209,8 @@
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
   
+  optimisations: re-delta-parent
+  
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
@@ -569,6 +573,8 @@
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
   
+  optimisations: re-delta-parent
+  
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
@@ -643,6 +649,8 @@
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
   
+  optimisations: re-delta-parent
+  
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
@@ -689,6 +697,8 @@
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
   
+  optimisations: re-delta-parent
+  
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
@@ -735,6 +745,8 @@
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
   
+  optimisations: re-delta-parent
+  
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
@@ -786,6 +798,8 @@
      preserved: dotencode, fncache, generaldelta, revlogv1, store
      removed: sparserevlog
   
+  optimisations: re-delta-parent
+  
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
@@ -835,6 +849,8 @@
      preserved: dotencode, fncache, generaldelta, revlogv1, store
      added: sparserevlog
   
+  optimisations: re-delta-parent
+  
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
@@ -923,6 +939,8 @@
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
   
+  optimisations: re-delta-fulladd
+  
   re-delta-fulladd
      each revision will be added as new content to the internal storage; this will likely drastically slow down execution time, but some extensions might need it
   
@@ -1135,6 +1153,8 @@
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
   
+  optimisations: re-delta-all
+  
   re-delta-all
      deltas within internal storage will be fully recomputed; this will likely drastically slow down execution time