diff --git a/src/stream/src/task/barrier_manager/managed_state.rs b/src/stream/src/task/barrier_manager/managed_state.rs
index 04ddce7f3e744..766a6a5943289 100644
--- a/src/stream/src/task/barrier_manager/managed_state.rs
+++ b/src/stream/src/task/barrier_manager/managed_state.rs
@@ -618,6 +618,7 @@ impl ManagedBarrierState {
                 .is_ok());
         }
 
+        // Spawn a trivial join handle to be compatible with the unit test
         if cfg!(test) {
             for actor_id in &actor_ids_to_collect {
                 if !self.actor_states.contains_key(actor_id) {