diff --git a/Synology-NAS-Guide.md b/Synology-NAS-Guide.md
index 67629e7..5fdd977 100644
--- a/Synology-NAS-Guide.md
+++ b/Synology-NAS-Guide.md
@@ -51,7 +51,7 @@ Note: Since `v3`, `acme.sh` uses Zerossl as the default Certificate Authority (C
 cd /usr/local/share/acme.sh
 export CERT_DOMAIN="your-domain.tld"
 export CERT_DNS="dns_cf"
-./acme.sh --issue --server letsencrypt --home . -d "$CERT_DOMAIN" --dns "$CERT_DNS" --ecc
+./acme.sh --issue --server letsencrypt --home . -d "$CERT_DOMAIN" --dns "$CERT_DNS" --keylength ec-384
 ```
 
 ## Deploy the default certificate