diff --git a/lisp/simple.el b/lisp/simple.el
index b770d9d7d33..9ef348f74dc 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -10863,6 +10863,10 @@ If the buffer doesn't exist, create it first."
   (pop-to-buffer-same-window (get-scratch-buffer-create)))
 
 (defun kill-buffer--possibly-save (buffer)
+  "Ask the user to confirm killing of a modified BUFFER.
+
+If the user confirms, optionally save BUFFER that is about to be
+killed."
   (let ((response
          (cadr
           (read-multiple-choice