diff --git a/Synology-NAS-Guide.md b/Synology-NAS-Guide.md
index 50b2a90..21f9939 100644
--- a/Synology-NAS-Guide.md
+++ b/Synology-NAS-Guide.md
@@ -53,6 +53,9 @@ export CERT_DNS="dns_cf"
 ```
 
 ## Deploy the default certificate
+
+This section has pre-updated, before [PR#5023](https://github.com/acmesh-official/acme.sh/pull/5023) got merged, you shall read [the old doc](https://github.com/acmesh-official/acme.sh/wiki/Synology-NAS-Guide/f26524f15d8e14fdc3c2cd7b75ce7eaf1d7eb532).
+
 We will use the [Synology DSM deployhook](https://github.com/acmesh-official/acme.sh/wiki/deployhooks#20-deploy-the-certificate-to-synology-dsm) to deploy our certificate. This will override the default certificate (if you haven't set any description for it), you can learn how to create new certificates to be used for other services later in this section.
 
 **The commands in the code block in this section assume you are still working in the same terminal and executed necessary commands described above.**