diff --git a/mosquitto/mosquitto.conf b/mosquitto/mosquitto.conf
index 00d85c6a..7add0aef 100644
--- a/mosquitto/mosquitto.conf
+++ b/mosquitto/mosquitto.conf
@@ -1,3 +1,5 @@
 listener 1883
 allow_anonymous true
+# simple password file created with the mosquitto_passwd utility
+# defines a single test_user with password test_password
 password_file /mosquitto/config/passwd
\ No newline at end of file