diff --git a/examples/config.ini b/examples/config.ini
index dca19a17d..4ff8e057a 100644
--- a/examples/config.ini
+++ b/examples/config.ini
@@ -181,6 +181,9 @@ minimum_ttl = 1440 ; One day
 #apikey =
 
 # https://circl.lu (Contact)
+# Access to CIRCL Passive DNS is only allowed to trusted partners in Luxembourg and abroad.
+# Contact http://services.circl.lu/contact/ if you would like access.
+# Include your affiliation and the foreseen use of the Passive DNS data.
 #[data_sources.CIRCL]
 #[data_sources.CIRCL.Credentials]
 #username =