diff --git a/breadcrumb.el b/breadcrumb.el
index 8c2fc99..93d9c81 100755
--- a/breadcrumb.el
+++ b/breadcrumb.el
@@ -740,6 +740,15 @@ If POS is nil, use current buffer location."
     (bury-buffer))
 )
 
+(defun toggle-read-only (f)
+  "Toggle the read-only status of the current buffer based on the
+value of f. If f is 1, make the buffer read-only. If f is 0,
+make the buffer writable."
+  (interactive "P")
+  (if (equal f 0)
+      (read-only-mode -1)
+    (read-only-mode 1)))
+
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