diff --git a/admin/admin.el b/admin/admin.el
index 4892045a690..7b9f01f64a1 100644
--- a/admin/admin.el
+++ b/admin/admin.el
@@ -143,6 +143,13 @@ Root must be the root of an Emacs source tree."
                          (not (equal (cadr oldversion) (cadr newversion)))))
          (newsfile (expand-file-name "etc/NEWS" root))
          (oldnewsfile (expand-file-name (format "etc/NEWS.%s" oldmajor) root)))
+    (unless (> (length newversion) 2)   ; pretest or release candidate?
+      (with-temp-buffer
+        (insert-file-contents newsfile)
+        (if (re-search-forward "^\\(+++ *\\|--- *\\)$" nil t)
+            (display-warning 'admin
+                             "NEWS file still contains temporary markup.
+Documentation changes might not have been completed!"))))
     (when (and majorbump
                (not (file-exists-p oldnewsfile)))
       (rename-file newsfile oldnewsfile)