using blank for completion

[gottlieb]

I prefer to have the "old-style" completion where space completes a word
and tab completes as far as possible.  In my emacs.d/init.el I have

(define-key minibuffer-local-filename-completion-map (kbd "SPC")
  'minibuffer-complete-word)
(define-key minibuffer-local-filename-must-match-map (kbd "SPC")
  'minibuffer-complete-word)

This has worked fine for several years and continues to work fine.
However, when I byte compile it I receive the warning

init.el:9:13:Warning: `minibuffer-local-filename-must-match-map' is an
    obsolete variable (as of 24.1).

What is the correct way to achieve this effect.

thanks,
allan