Explicitly require nix and nix-flake from nix-mode package

README.org

@@ -1008,6 +1008,15 @@ Set treesit to fontify all elements, default was 3 (out of 4)
            rust-mode))
 #+end_src
 ** Language-specific settings
+*** Nix
+#+begin_src emacs-lisp
+  (use-package nix-mode
+    :mode "\\.nix\\'"
+    :config
+    (require 'nix)
+    (require 'nix-flake))
+#+end_src
+
 *** Python
 Set fill column to 88 and enable display in python buffers
 #+begin_src emacs-lisp :tangle yes