diff --git a/ivy.el b/ivy.el
index 659ba3e2..1ca3bceb 100644
--- a/ivy.el
+++ b/ivy.el
@@ -2984,6 +2984,9 @@ tries to ensure that it does not change depending on the number of candidates."
   "Minibuffer setting for `truncate-lines'."
   :type 'boolean)
 
+(defvar mwheel-scroll-up-function)
+(defvar mwheel-scroll-down-function)
+
 (defun ivy--minibuffer-setup ()
   "Setup ivy completion in the minibuffer."
   (setq-local mwheel-scroll-up-function 'ivy-next-line)