diff --git a/mod_default_rooms/README.md b/mod_default_rooms/README.md
index e42fd36..13b8b19 100644
--- a/mod_default_rooms/README.md
+++ b/mod_default_rooms/README.md
@@ -20,11 +20,10 @@ following:
 
 ```yaml
 modules:
-  # [...]
   mod_default_rooms:
     rooms:
-      - "foo@conference.example.net"
-      - "bar@conference.example.org"
+      - foo@conference.example.net
+      - bar@conference.example.org
 ```
 
 The configurable `mod_default_rooms` options are:
diff --git a/mod_default_rooms/src/mod_default_rooms.erl b/mod_default_rooms/src/mod_default_rooms.erl
index 5b4fde2..01ee187 100644
--- a/mod_default_rooms/src/mod_default_rooms.erl
+++ b/mod_default_rooms/src/mod_default_rooms.erl
@@ -52,11 +52,11 @@ stop(Host) ->
 reload(_Host, _NewOpts, _OldOpts) ->
     ok.
 
--spec mod_opt_type(atom()) -> fun((term()) -> term()).
+-spec mod_opt_type(atom()) -> econf:validator().
 mod_opt_type(auto_join) ->
-    fun (B) when is_boolean(B) -> B end;
+    econf:bool();
 mod_opt_type(rooms) ->
-    fun (Rs) -> [jid:decode(iolist_to_binary(R)) || R <- Rs] end.
+    econf:list(econf:jid(), [unique]).
 
 -spec mod_options(binary()) -> [{atom(), any()}].
 mod_options(_Host) ->