diff --git a/lisp/outline.el b/lisp/outline.el
index 392c60a4604..8dcb7263da3 100644
--- a/lisp/outline.el
+++ b/lisp/outline.el
@@ -267,10 +267,13 @@ non-nil and point is located on the heading line.")
                              ;; This is equivalent to adding ".*" in the regexp below.
                              (set-match-data
                               (list (match-beginning 0)
-                                    (save-excursion
-                                      (save-match-data
-                                        (re-search-forward
-                                         (concat ".*" outline-heading-end-regexp) nil t)))))
+                                    (or (save-excursion
+                                          (save-match-data
+                                            (re-search-forward
+                                             (concat ".*" outline-heading-end-regexp) nil t)))
+                                        ;; Fall back to eol when there is no newline
+                                        ;; at the end of outline at eob.
+                                        (pos-eol))))
                              ret)))
                       (concat "^\\(?:" outline-regexp "\\).*" outline-heading-end-regexp))
                   0 '(if outline-minor-mode
@@ -531,10 +534,13 @@ outline font-lock faces to those of major mode."
                    ;; This is equivalent to adding ".*" in the regexp above.
                    (set-match-data
                     (list (match-beginning 0)
-                          (save-excursion
-                            (save-match-data
-                              (re-search-forward
-                               (concat ".*" outline-heading-end-regexp) nil t)))))
+                          (or (save-excursion
+                                (save-match-data
+                                  (re-search-forward
+                                   (concat ".*" outline-heading-end-regexp) nil t)))
+                              ;; Fall back to eol when there is no newline
+                              ;; at the end of outline at eob.
+                              (pos-eol))))
                    ret)
                (re-search-forward regexp nil t))
         (let ((overlay (make-overlay (match-beginning 0) (match-end 0))))
@@ -2030,12 +2036,7 @@ With a prefix argument, show headings up to that LEVEL."
        from to)
       (restore-buffer-modified-p modified))))
 
-(defvar outline-after-change-functions nil
-  "Hook run before updating buttons in a region in outline-mode.
-Called with three arguments (BEG END DUMMY).  Don't use DUMMY.")
-
 (defun outline--fix-buttons (&optional beg end)
-  (run-hook-with-args 'outline-after-change-functions beg end 0)
   ;; Handle whole lines
   (save-excursion
     (setq beg (if (null beg) (point-min) (goto-char beg) (pos-bol)))