diff --git a/Synology-NAS-Guide.md b/Synology-NAS-Guide.md
index c3c4cf1..fd5f0f8 100644
--- a/Synology-NAS-Guide.md
+++ b/Synology-NAS-Guide.md
@@ -84,4 +84,10 @@ Now you should all good.
 
 --------------------------------------------------------------------------------------------------------------------
 
-HTH
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+To fix the broken environment after Synology DSM upgrade, you can
+```
+$ cd /urs/local/sbin/acme.sh
+$ ./acme.sh --upgrade --nocron --home /usr/local/sbin/acme.sh
+```
+or manually add below line into /root/.profile
+`. "/usr/local/sbin/acme.sh/acme.sh.env"`
\ No newline at end of file