diff --git a/src/undo.c b/src/undo.c
index 331c1e6..171e817 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -3669,6 +3669,28 @@
     rettv->vval.v_string = NULL;
 #endif
 }
+#ifdef FEAT_PERSISTENT_UNDO
+/*
+ * Reset undofile option and delete the undofile
+ */
+    void
+u_undofile_reset_and_delete(buf_T *buf)
+{
+    char_u *file_name;
+
+    if (!buf->b_p_udf)
+	return;
+
+    file_name = u_get_undo_file_name(buf->b_ffname, TRUE);
+    if (file_name != NULL)
+    {
+	mch_remove(file_name);
+	vim_free(file_name);
+    }
+
+    set_option_value((char_u *)"undofile", 0L, NULL, OPT_LOCAL);
+}
+ #endif
 
 /*
  * "undotree()" function