diff --git a/etc/NEWS b/etc/NEWS
index 3021ad42a12..1f99eb22a38 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -3931,7 +3931,20 @@ A major mode based on 'conf-mode' for editing ".npmrc" files.
 ** New major modes based on the tree-sitter library
 
 *** New major mode 'markdown-ts-mode'.
-A major mode based on the tree-sitter library for editing Markdown files.
+A major mode based on the tree-sitter library for editing Markdown
+files.  This is now the default major mode for Markdown files.  If you
+don't have the necessary tree-sitter grammar libraries installed, or if
+your Emacs was built without tree-sitter support, Emacs will now show a
+warning to that effect when you visit a Markdown file.  If you don't
+want to use this mode and want to avoid these warnings, add the
+following to your init file:
+
+  (add-to-list 'auto-mode-alist '("\\.md\\'" . fundamental-mode))
+  (add-to-list 'auto-mode-alist '("\\.markdown\\'" . fundamental-mode))
+  (add-to-list 'auto-mode-alist '("\\.mdx\\'" . fundamental-mode))
+
+This will cause Emacs to visit Markdown files in Fundamental mode, which
+was the default before this mode was added to Emacs.
 
 *** New major mode 'mhtml-ts-mode'.
 An optional major mode based on the tree-sitter library for editing HTML