declared defvar is reported as unbound

[Fuco1]

(defvar my-custom-var-1
  (or
   (if (memq completing-read-function
             '(ido-completing-read+
               ido-completing-read
               completing-read-ido-ubiquitous
               completing-read-ido
               ido-ubiquitous-completing-read))
       'completing-read-default
     completing-read-function)
   'completing-read-default))

(defun myfun1 (arg) arg)

;; Elsa thinks the argument's type is Unbound
(myfun1 my-custom-var-1)

Related to #164