diff --git a/lisp/treesit.el b/lisp/treesit.el
index 962a6fc3cf8..f5d30be52bb 100644
--- a/lisp/treesit.el
+++ b/lisp/treesit.el
@@ -1075,17 +1075,56 @@ treesit-font-lock-fontify-region
                                face (treesit-node-type node))))))))))))
   `(jit-lock-bounds ,start . ,end))
 
+(defvar treesit--notifier-ranges nil)
+(defvar treesit--notifier-context 'direct)
+
 (defun treesit--font-lock-notifier (ranges parser)
   "Ensures updated parts of the parse-tree are refontified.
+And re-syntax-propertized.
 RANGES is a list of (BEG . END) ranges, PARSER is the tree-sitter
 parser notifying of the change."
   (with-current-buffer (treesit-parser-buffer parser)
-    (dolist (range ranges)
-      (when treesit--font-lock-verbose
-        (message "Notifier received range: %s-%s"
-                 (car range) (cdr range)))
-      (with-silent-modifications
-        (put-text-property (car range) (cdr range) 'fontified nil)))))
+    (unless (eq treesit--notifier-context 'direct)
+      (setq treesit--notifier-ranges (append treesit--notifier-ranges ranges)))
+    (message "notifier context %s ranges %s" treesit--notifier-context ranges)
+    (when ranges
+      (unless (eq treesit--notifier-context 'font-lock)
+        (when treesit-font-lock-settings
+          (with-silent-modifications
+            (dolist (range ranges)
+              (when treesit--font-lock-verbose
+                (message "Notifier received range: %s-%s"
+                         (car range) (cdr range)))
+              ;; (backtrace)
+              (put-text-property (car range) (cdr range) 'fontified nil)))))
+      (unless (eq treesit--notifier-context 'syntax)
+        (when syntax-propertize-function
+          (syntax-ppss-flush-cache (cl-loop for r in ranges
+                                            minimize (car r))))))))
+
+(defun treesit--syntax-extend-region (beg end &optional font-lock-p)
+  (let (treesit--notifier-ranges
+        (treesit--notifier-context (if font-lock-p 'font-lock 'syntax)))
+    (treesit-buffer-root-node (treesit-language-at (point)))
+    (when treesit--notifier-ranges
+      ;; (message "some ranges received %S while beg end %s %s" treesit--notifier-ranges beg end)
+      ;; Some updates received from `treesit_ensure_parsed'.
+      (cl-loop for range in treesit--notifier-ranges
+               if (or (<= (car range) beg (cdr range))
+                      (<= (car range) end (cdr range)))
+               return (cons (min (car range) beg)
+                            (max (cdr range) end))))))
+
+(defun treesit--font-lock-extend-region ()
+  (defvar font-lock-beg)
+  (defvar font-lock-end)
+  ;; (message "called treesit--font-lock-extend-region")
+  (let ((new (treesit--syntax-extend-region font-lock-beg font-lock-end t)))
+    (when new
+      ;; (message "eeextended to %S" new)
+      (setq font-lock-beg (car new))
+      (setq font-lock-end (cdr new))
+      t)))
 
 ;;; Indent
 
@@ -2391,7 +2430,9 @@ treesit-major-mode-setup
     (treesit-font-lock-recompute-features)
     (dolist (parser (treesit-parser-list))
       (treesit-parser-add-notifier
-       parser #'treesit--font-lock-notifier)))
+       parser #'treesit--font-lock-notifier))
+    (push #'treesit--font-lock-extend-region font-lock-extend-region-functions)
+    (push #'treesit--syntax-extend-region syntax-propertize-extend-region-functions))
   ;; Indent.
   (when treesit-simple-indent-rules
     (setq-local treesit-simple-indent-rules