diff --git a/dbms/src/Interpreters/Cluster.cpp b/dbms/src/Interpreters/Cluster.cpp
index e76ec26f385..9b090a2a9e6 100644
--- a/dbms/src/Interpreters/Cluster.cpp
+++ b/dbms/src/Interpreters/Cluster.cpp
@@ -400,12 +400,12 @@ std::unique_ptr<Cluster> Cluster::getClusterWithSingleShard(size_t index) const
     return std::unique_ptr<Cluster>{ new Cluster(*this, {index}) };
 }
 
-std::unique_ptr<Cluster> Cluster::getClusterWithMultipleShards(std::vector<size_t> indices) const
+std::unique_ptr<Cluster> Cluster::getClusterWithMultipleShards(const std::vector<size_t> & indices) const
 {
     return std::unique_ptr<Cluster>{ new Cluster(*this, indices) };
 }
 
-Cluster::Cluster(const Cluster & from, std::vector<size_t> indices)
+Cluster::Cluster(const Cluster & from, const std::vector<size_t> & indices)
     : shards_info{}
 {
     for (size_t index : indices)