diff --git a/dbms/include/DB/Common/HashTable/HashMap.h b/dbms/include/DB/Common/HashTable/HashMap.h
index 82664e21a59..b73ccb7ab88 100644
--- a/dbms/include/DB/Common/HashTable/HashMap.h
+++ b/dbms/include/DB/Common/HashTable/HashMap.h
@@ -129,6 +129,8 @@ public:
 	typedef typename Cell::Mapped mapped_type;
 	typedef typename Cell::value_type value_type;
 
+	using HashTable<Key, Cell, Hash, Grower, Allocator>::HashTable;
+
 	mapped_type & operator[](Key x)
 	{
 		typename HashMapTable::iterator it;
diff --git a/dbms/include/DB/Common/HashTable/HashTable.h b/dbms/include/DB/Common/HashTable/HashTable.h
index 16f07e526a2..92e656456cd 100644
--- a/dbms/include/DB/Common/HashTable/HashTable.h
+++ b/dbms/include/DB/Common/HashTable/HashTable.h
@@ -240,7 +240,7 @@ protected:
 	Grower grower;
 
 #ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
-	mutable size_t collisions;
+	mutable size_t collisions = 0;
 #endif
 
 	/// Найти ячейку с тем же ключём или пустую ячейку, начиная с заданного места и далее по цепочке разрешения коллизий.
@@ -372,10 +372,14 @@ public:
 		if (Cell::need_zero_value_storage)
 			this->zeroValue()->setZero();
 		alloc(grower);
+	}
 
-#ifdef DBMS_HASH_MAP_COUNT_COLLISIONS
-		collisions = 0;
-#endif
+	HashTable(size_t reserve_for_num_elements)
+	{
+		if (Cell::need_zero_value_storage)
+			this->zeroValue()->setZero();
+		grower.set(reserve_for_num_elements);
+		alloc(grower);
 	}
 
 	~HashTable()