diff --git a/doc/bird.sgml b/doc/bird.sgml
index 33f6418f..401b4035 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -783,11 +783,12 @@ agreement").
 
 <descrip>
 	<tag><label id="proto-pass-id">id <M>num</M></tag>
-	ID of the password, (1-255). If it is not used, BIRD will choose ID based
-	on an order of the password item in the interface. For example, second
-	password item in one interface will have default ID 2. ID is used by
-	some routing protocols to identify which password was used to
-	authenticate protocol packets.
+	ID of the password, (0-255). If it is not specified, BIRD will choose ID
+	based on an order of the password item in the interface, starting from
+	1. For example, second password item in one interface will have default
+	ID 2. ID 0 is allowed by BIRD, but some other implementations may not
+	allow it. ID is used by some routing protocols to identify which
+	password was used to authenticate protocol packets.
 
 	<tag><label id="proto-pass-gen-from">generate from "<m/time/"</tag>
 	The start time of the usage of the password for packet signing.
diff --git a/nest/config.Y b/nest/config.Y
index bd1157c6..f2f1df34 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -480,7 +480,7 @@ password_item_params:
  | ACCEPT TO time ';' password_item_params { this_p_item->accto = $3; }
  | FROM time ';' password_item_params { this_p_item->genfrom = this_p_item->accfrom = $2; }
  | TO time ';' password_item_params { this_p_item->gento = this_p_item->accto = $2; }
- | ID expr ';' password_item_params { this_p_item->id = $2; if ($2 <= 0) cf_error("Password ID has to be greated than zero."); }
+ | ID expr ';' password_item_params { this_p_item->id = $2; if ($2 > 255) cf_error("Password ID must be in range 0-255"); }
  | ALGORITHM password_algorithm ';' password_item_params { this_p_item->alg = $2; }
  ;