diff --git a/src/api/client_server/sync/msc4186.rs b/src/api/client_server/sync/msc4186.rs
index b7f423a5..74f8a397 100644
--- a/src/api/client_server/sync/msc4186.rs
+++ b/src/api/client_server/sync/msc4186.rs
@@ -615,7 +615,7 @@ pub(crate) async fn sync_events_v5_route(
     }
 
     Ok(Ra(sync_events::v5::Response {
-        txn_id: body.txn_id.clone(),
+        txn_id: None,
         pos: next_batch.to_string(),
         lists,
         rooms,