;(defvar dired-kept-versions 2
; "*When cleaning directory, number of versions to keep.")
-(defcustom delete-old-versions nil
+(defcustom delete-old-versions (when noninteractive 'leave)
"*If t, delete excess backup versions silently.
If nil, ask confirmation. Any other value prevents any trimming."
:type '(choice (const :tag "Delete" t)