diff --git a/doom.d/config.el b/doom.d/config.el
index 5f6b567..cf1c194 100644
--- a/doom.d/config.el
+++ b/doom.d/config.el
@@ -214,3 +214,5 @@
     (my-42-header)))
 
 (add-hook 'before-save-hook #'my-42-header-before-save-hook)
+
+(add-to-list 'auto-mode-alist '("\\.jjdescription\\'" . diff-mode))