diff --git a/.emacs.d/init.el b/.emacs.d/init.el
index 5836548..4d5aef4 100644
--- a/.emacs.d/init.el
+++ b/.emacs.d/init.el
@@ -69,6 +69,7 @@
 ;; file extensions
 (add-to-list 'auto-mode-alist '("\\.eml\\'" . mail-mode))
 (add-to-list 'auto-mode-alist '("\\.scd\\'" . markdown-mode))
+(add-to-list 'auto-mode-alist '("\\.3lua\\'" . nroff-mode))
 
 ;; treesitter modes
 (setq major-mode-remap-alist