Flycheck UsePackage with C++11

I use use-package for my emacs configuration. Unfortunately I cannot properly configure the flycheck package to work with C++11 extension.

Here what I have so far:

;; == Flycheck ==
(use-package flycheck
  :ensure t
  :defer t
  :init
  (global-flycheck-mode)
  :config
  (setq flycheck-clang-language-standard "c++11"))

Although I set the proper variable, the flycheck gives me an error on c++11 syntax (e.g. auto i = 10).

What am I missing?