diff --git a/doom-modeline.el b/doom-modeline.el
index 82d3cd1..2e05089 100644
--- a/doom-modeline.el
+++ b/doom-modeline.el
@@ -833,8 +833,9 @@ Uses `all-the-icons-material' to fetch the icon."
 (when (>= emacs-major-version 26)
   (add-variable-watcher
    'buffer-read-only
-   (lambda (_sym _val op _where)
+   (lambda (_sym val op _where)
      (when (eq op 'set)
+       (setq buffer-read-only val)
        (doom-modeline-update-buffer-file-state-icon)))))
 
 (defvar-local doom-modeline--buffer-file-name nil)