diff --git a/src/service/globals/mod.rs b/src/service/globals/mod.rs
index 90d6df4a..9bf325d5 100644
--- a/src/service/globals/mod.rs
+++ b/src/service/globals/mod.rs
@@ -1,10 +1,9 @@
 mod data;
 pub use data::{Data, SigningKeys};
 
-use hmac::digest::typenum::Pow;
 use ruma::{
     serde::Base64, MilliSecondsSinceUnixEpoch, OwnedDeviceId, OwnedEventId, OwnedRoomAliasId,
-    OwnedRoomId, OwnedRoomOrAliasId, OwnedServerName, OwnedUserId, RoomAliasId, RoomId,
+    OwnedRoomId, OwnedRoomOrAliasId, OwnedServerName, OwnedUserId, RoomAliasId,
 };
 
 use crate::api::{client_server::get_alias_helper, server_server::DestinationResponse};
@@ -25,7 +24,6 @@ use std::{
     future::{self, Future},
     iter,
     net::{IpAddr, SocketAddr},
-    ops::Deref,
     path::PathBuf,
     str::FromStr,
     sync::{
@@ -511,29 +509,27 @@ impl Service {
     pub async fn default_rooms(&self) -> Result<BTreeSet<OwnedRoomId>> {
         let server_name = &self.config.server_name;
 
-        let fallback = || {
-            format!("#{s}:{server_name}")
-                .parse()
-                .map_err(|_| Error::bad_config("Invalid opaque identifier."))
-        };
-
-        let f = |s| match OwnedRoomOrAliasId::from_str(s).map(OwnedRoomId::try_from) {
-            Ok(Ok(room_id)) => room_id
-                .server_name()
-                .ok_or_else(|| Error::bad_config("Invalid room ID due to missing server name."))
-                .map(|_| room_id),
-            result => get_alias_helper(result.map(Result::unwrap_err).or_else(fallback)?)
+        let f = |s| async move {
+            match OwnedRoomOrAliasId::from_str(s).map(OwnedRoomId::try_from) {
+                Ok(Ok(room_id)) => room_id
+                    .server_name()
+                    .ok_or_else(|| Error::bad_config("Invalid room ID due to missing server name."))
+                    .map(|_| room_id.clone()),
+                result => get_alias_helper(result.map(Result::unwrap_err).or_else(|_| {
+                    format!("#{s}:{server_name}")
+                        .parse()
+                        .map_err(|_| Error::bad_config("Invalid opaque identifier."))
+                })?)
                 .await
                 .map(|response| response.room_id),
+            }
         };
 
-        self.config
-            .default_rooms
-            .rooms
-            .iter()
-            .map(String::as_str)
-            .map(|s| f)
-            .collect::<Result<_>>()
+        let rooms = self.config.default_rooms.rooms.iter().map(String::as_str);
+        futures_util::future::try_join_all(rooms.map(f))
+            .await
+            .map(Vec::into_iter)
+            .map(BTreeSet::from_iter)
     }
 
     pub fn shutdown(&self) {