diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 46196e85a65..f0eb059642e 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,7 @@
 2010-04-20  Glenn Morris  <rgm@gnu.org>
 
+	* emacs-lisp/lisp.el (lisp-completion-at-point): Give it a doc string.
+
 	* minibuffer.el (completion-at-point): Doc fix.
 
 2010-04-18  Chong Yidong  <cyd@stupidchicken.com>
diff --git a/lisp/emacs-lisp/lisp.el b/lisp/emacs-lisp/lisp.el
index da482e715b1..54fa4d615cd 100644
--- a/lisp/emacs-lisp/lisp.el
+++ b/lisp/emacs-lisp/lisp.el
@@ -627,9 +627,10 @@ considered."
     (let ((completion-annotate-function (plist-get plist :annotate-function)))
       (completion-in-region (nth 0 data) (nth 1 data) (nth 2 data)
                             (plist-get plist :predicate)))))
-    
+
 
 (defun lisp-completion-at-point (&optional predicate)
+  "Function used for `completion-at-point-functions' in `emacs-lisp-mode'."
   ;; FIXME: the `end' could be after point?
   (let* ((end (point))
          (beg (with-syntax-table emacs-lisp-mode-syntax-table