diff --git a/etc/example.conf b/etc/example.conf
index 70e20231..4816aa9e 100644
--- a/etc/example.conf
+++ b/etc/example.conf
@@ -22,10 +22,11 @@ username=piler
 ; The default is 7 years + 2 days (=7*365+2=2557 days)
 default_retention_days=2557
 
-; this is a 16 character long vector
-; after the installation you must not change it ever
-; otherwise you can't access your emails
-;iv=****************
+; The initialization vector for encryption.
+; By now it has become obsolete. Don't use it for
+; new installations. However, if you used it before
+; then you must keep it as it is.
+;iv=
 
 ; whether to encrypt messages (1) or not (0).
 ; Make sure to set this value to your needs right after installing piler,