diff --git a/src/config/mod.rs b/src/config/mod.rs
index 9d2b9e44..7b1f54b4 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -60,7 +60,7 @@ pub struct Config {
     #[serde(default = "default_default_room_version")]
     pub default_room_version: RoomVersionId,
     #[serde(default = "Vec::new")]
-    pub join_by_default: Vec<String>,
+    pub default_rooms: Vec<OwnedRoomId>,
     #[serde(default)]
     pub well_known: WellKnownConfig,
     #[serde(default = "false_fn")]