diff --git a/oni-elisp.el b/oni-elisp.el
index 836df7e..3b34ed2 100644
--- a/oni-elisp.el
+++ b/oni-elisp.el
@@ -46,6 +46,9 @@
 
 (define-key emacs-lisp-mode-map (kbd "C-c C-v") erefactor-map)
 
+;;;###autoload
+(add-to-list 'auto-mode-alist '("/Cask\\'" . emacs-lisp-mode))
+
 ;;;###autoload(with-eval-after-load 'elisp-mode (require 'oni-elisp))
 ;;;###autoload(with-eval-after-load 'ielm (require 'oni-elisp))