diff --git a/docs/inwx.md b/docs/inwx.md
index 4b06b50c9..2baa9d9e9 100644
--- a/docs/inwx.md
+++ b/docs/inwx.md
@@ -2,6 +2,8 @@
 
 ## Configuration
 
+You must configure a DynDNS Account in INWX and use the configured account and hostname. See https://www.inwx.com/en/offer/dyndns.
+
 ### Example
 
 ```json
@@ -21,7 +23,7 @@
 
 ### Compulsory parameters
 
-- `"domain"` is the domain to update. It can be `example.com` (root domain) or `sub.example.com` (subdomain of `example.com`).
+- `"domain"` is the domain to update. This must be the domain configured for the DynDNS Account.
 - `"username"`
 - `"password"`