diff --git a/packages/alias-to-sieve/README.md b/packages/alias-to-sieve/README.md
index 339219c..6d0cb22 100644
--- a/packages/alias-to-sieve/README.md
+++ b/packages/alias-to-sieve/README.md
@@ -50,6 +50,8 @@ discard;
 
 ```
 
+If you have multiple domains, do `$ ./alias_to_sieve simple.aliases example.com other.aliases example.org`.
+
 ## Limitations
 You cannot use apostrophes (') in any mail addresses although allowed by [RFC 5322](https://www.rfc-editor.org/rfc/rfc5322) since they would break termination of strings in sieve.