diff --git a/astra-sim-alibabacloud/astra-sim/system/MockNcclGroup.cc b/astra-sim-alibabacloud/astra-sim/system/MockNcclGroup.cc
index 52cfc03cd..484b6f11d 100644
--- a/astra-sim-alibabacloud/astra-sim/system/MockNcclGroup.cc
+++ b/astra-sim-alibabacloud/astra-sim/system/MockNcclGroup.cc
@@ -2022,7 +2022,7 @@ namespace MockNccl {
         q.push(current->right);
       }
     }
-    return node2treenode[(nodes[rank2index[root->node]+1]) % nodes.size()];
+    return node2treenode[nodes[(rank2index[root->node]+1) % nodes.size()]];
   }
 
   ncclInfo* MockNcclGroup::get_algo_proto_info(
@@ -2100,4 +2100,4 @@ namespace MockNccl {
     return info;
     }
   }
-}
\ No newline at end of file
+}