diff --git a/ruma-federation-api/src/directory/get_public_rooms/v1.rs b/ruma-federation-api/src/directory/get_public_rooms/v1.rs
index 351d5888..cb470ca4 100644
--- a/ruma-federation-api/src/directory/get_public_rooms/v1.rs
+++ b/ruma-federation-api/src/directory/get_public_rooms/v1.rs
@@ -58,7 +58,7 @@ pub struct PublicRoomsChunk {
     pub aliases: Vec<RoomAliasId>,
     /// The canonical alias of the room, if any.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub canonical_alias: Option<String>,
+    pub canonical_alias: Option<RoomAliasId>,
     /// The name of the room, if any.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub name: Option<String>,