diff --git a/src/api/client_server/sync/msc3575.rs b/src/api/client_server/sync/msc3575.rs
index 31333eaf..e1ede5de 100644
--- a/src/api/client_server/sync/msc3575.rs
+++ b/src/api/client_server/sync/msc3575.rs
@@ -305,64 +305,59 @@ pub(crate) async fn sync_events_v4_route(
 
         let mut new_known_rooms = BTreeSet::new();
 
+        let mut ops = Vec::new();
+        for (mut from, mut to) in list.ranges {
+            from = from.clamp(
+                uint!(0),
+                UInt::try_from(all_joined_rooms.len() - 1).unwrap_or(UInt::MAX),
+            );
+            to = to.clamp(
+                from,
+                UInt::try_from(all_joined_rooms.len() - 1).unwrap_or(UInt::MAX),
+            );
+            let room_ids =
+                all_joined_rooms[from.try_into().unwrap_or(usize::MAX)
+                    ..=to.try_into().unwrap_or(usize::MAX)]
+                    .to_vec();
+
+            new_known_rooms.extend(room_ids.iter().cloned());
+            for room_id in &room_ids {
+                let todo_room = todo_rooms.entry(room_id.clone()).or_insert((
+                    BTreeSet::new(),
+                    0,
+                    u64::MAX,
+                ));
+                let limit = list
+                    .room_details
+                    .timeline_limit
+                    .map_or(10, u64::from)
+                    .min(100);
+                todo_room
+                    .0
+                    .extend(list.room_details.required_state.iter().cloned());
+                todo_room.1 = todo_room.1.max(limit);
+                // 0 means unknown because it got out of date
+                todo_room.2 = todo_room.2.min(
+                    known_rooms
+                        .get(&list_id)
+                        .and_then(|k| k.get(room_id))
+                        .copied()
+                        .unwrap_or(0),
+                );
+            }
+            ops.push(sync_events::v4::SyncOp {
+                op: SlidingOp::Sync,
+                range: Some((from, to)),
+                index: None,
+                room_ids,
+                room_id: None,
+            });
+        }
+
         lists.insert(
             list_id.clone(),
             sync_events::v4::SyncList {
-                ops: list
-                    .ranges
-                    .into_iter()
-                    .map(|mut r| {
-                        r.0 = r.0.clamp(
-                            uint!(0),
-                            UInt::try_from(all_joined_rooms.len() - 1)
-                                .unwrap_or(UInt::MAX),
-                        );
-                        r.1 = r.1.clamp(
-                            r.0,
-                            UInt::try_from(all_joined_rooms.len() - 1)
-                                .unwrap_or(UInt::MAX),
-                        );
-                        let room_ids = all_joined_rooms[r
-                            .0
-                            .try_into()
-                            .unwrap_or(usize::MAX)
-                            ..=r.1.try_into().unwrap_or(usize::MAX)]
-                            .to_vec();
-                        new_known_rooms.extend(room_ids.iter().cloned());
-                        for room_id in &room_ids {
-                            let todo_room = todo_rooms
-                                .entry(room_id.clone())
-                                .or_insert((BTreeSet::new(), 0, u64::MAX));
-                            let limit = list
-                                .room_details
-                                .timeline_limit
-                                .map_or(10, u64::from)
-                                .min(100);
-                            todo_room.0.extend(
-                                list.room_details
-                                    .required_state
-                                    .iter()
-                                    .cloned(),
-                            );
-                            todo_room.1 = todo_room.1.max(limit);
-                            // 0 means unknown because it got out of date
-                            todo_room.2 = todo_room.2.min(
-                                known_rooms
-                                    .get(&list_id)
-                                    .and_then(|k| k.get(room_id))
-                                    .copied()
-                                    .unwrap_or(0),
-                            );
-                        }
-                        sync_events::v4::SyncOp {
-                            op: SlidingOp::Sync,
-                            range: Some(r),
-                            index: None,
-                            room_ids,
-                            room_id: None,
-                        }
-                    })
-                    .collect(),
+                ops,
                 count: UInt::try_from(all_joined_rooms.len())
                     .unwrap_or(UInt::MAX),
             },