diff --git a/init.el b/init.el
index 862a2e2..febe047 100644
--- a/init.el
+++ b/init.el
@@ -51,7 +51,7 @@
 
 (setup-define :mode
   (lambda (ext)
-    `(add-to-list 'auto-mode-alist '(,ext . setup-mode)))
+    `(add-to-list 'auto-mode-alist (cons ,ext setup-mode)))
   :documentation "Add SETUP-MODE to `auto-mode-alist' for EXTENSION."
   :repeatable t)