Loading a package after another one which doesn't provide itself

[DamienCassou]

I would like use-package to load anzu only when isearch is loaded. I tried:

(use-package anzu
  :after (isearch)
  :diminish anzu-mode
  :bind (("M-%" . anzu-query-replace)
         ("C-M-%" . anzu-query-replace-regexp))
  :config
  (progn
    (global-anzu-mode +1)
    (define-key isearch-mode-map [remap isearch-query-replace] #'anzu-isearch-query-replace)
    (define-key isearch-mode-map [remap isearch-query-replace-regexp] #'anzu-isearch-query-replace-regexp)))

but it doesn't work and I guess that's because isearch doesn't have any (provide 'isearch) line (I've just sent a patch to bug-gnu-emacs). Is there any solution from use-package?

[npostavs]

I would like use-package to load anzu only when isearch is loaded. I tried:

isearch is preloaded, so "only when isearch is loaded" means always.