diff --git a/emacs/.emacs.d/init.el b/emacs/.emacs.d/init.el
index fb11d21..ae92035 100644
--- a/emacs/.emacs.d/init.el
+++ b/emacs/.emacs.d/init.el
@@ -235,6 +235,9 @@
 (global-diff-hl-mode)
 
 (defun oni:with-diff-hl-p4-args (orig-fun &rest args)
+  "Add Perforce-specific command-line arguments to `diff-hl-mode'.
+
+ORIG-FUN is the function being wrapped, ARGS are the arguments specified"
   (let ((p4-lowlevel-diff-switches '("-du0")))
     (apply orig-fun args)))