-(defalias 'icalendar-extract-ical-from-buffer 'icalendar-import-buffer)
-(make-obsolete 'icalendar-extract-ical-from-buffer 'icalendar-import-buffer "22.1")
+(define-obsolete-function-alias 'icalendar-extract-ical-from-buffer
+ 'icalendar-import-buffer "22.1")