diff --git a/dbms/src/Storages/MergeTree/MergeTreeData.cpp b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
index 503d1708300..ea51159d9ba 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeData.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
@@ -1439,10 +1439,10 @@ void MergeTreeData::alterDataPart(
     const NamesAndTypesList & new_columns,
     const IndicesASTs & new_indices,
     bool skip_sanity_checks,
-    AlterDataPartTransactionPtr& transaction)
+    AlterDataPartTransactionPtr & transaction)
 {
     ExpressionActionsPtr expression;
-    const auto& part = transaction->getDataPart();
+    const auto & part = transaction->getDataPart();
     bool force_update_metadata;
     createConvertExpression(part, part->columns, new_columns,
             getIndices().indices, new_indices,
diff --git a/dbms/src/Storages/MergeTree/MergeTreeData.h b/dbms/src/Storages/MergeTree/MergeTreeData.h
index 98ce5b4c371..fecddb28540 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeData.h
+++ b/dbms/src/Storages/MergeTree/MergeTreeData.h
@@ -228,7 +228,7 @@ public:
         const DataPart::Checksums & getNewChecksums() const { return new_checksums; }
 
         AlterDataPartTransaction(DataPartPtr data_part_) : data_part(data_part_), alter_lock(data_part->alter_mutex) {}
-        const DataPartPtr& getDataPart() const { return data_part; }
+        const DataPartPtr & getDataPart() const { return data_part; }
         bool isValid() const;
 
     private:
diff --git a/dbms/src/Storages/StorageMergeTree.cpp b/dbms/src/Storages/StorageMergeTree.cpp
index d80a05a8bab..fe66a11e6d6 100644
--- a/dbms/src/Storages/StorageMergeTree.cpp
+++ b/dbms/src/Storages/StorageMergeTree.cpp
@@ -203,7 +203,7 @@ std::vector<MergeTreeData::AlterDataPartTransactionPtr> StorageMergeTree::prepar
     std::vector<MergeTreeData::AlterDataPartTransactionPtr> transactions;
     transactions.reserve(parts.size());
 
-    const auto& columns_for_parts = new_columns.getAllPhysical();
+    const auto & columns_for_parts = new_columns.getAllPhysical();
 
     const Settings & settings = context.getSettingsRef();
     size_t thread_pool_size = std::min<size_t>(parts.size(), settings.max_alter_threads);
@@ -215,7 +215,7 @@ std::vector<MergeTreeData::AlterDataPartTransactionPtr> StorageMergeTree::prepar
         transactions.push_back(std::make_unique<MergeTreeData::AlterDataPartTransaction>(part));
 
         thread_pool.schedule(
-            [this, &transaction = transactions.back(), &columns_for_parts, &new_indices = new_indices.indices]
+            [this, & transaction = transactions.back(), & columns_for_parts, & new_indices = new_indices.indices]
             {
                 this->alterDataPart(columns_for_parts, new_indices, false, transaction);
             }