diff --git a/mercurial/repair.py b/mercurial/repair.py
--- a/mercurial/repair.py
+++ b/mercurial/repair.py
@@ -244,6 +244,9 @@ def strip(ui, repo, nodelist, backup=Tru
             vfs.unlink(tmpbundlefile)
 
     repo.destroyed()
+    # return the backup file path (or None if 'backup' was False) so
+    # extensions can use it
+    return backupfile
 
 def rebuildfncache(ui, repo):
     """Rebuilds the fncache file from repo history.