diff --git a/dbms/include/DB/Common/FileChecker.h b/dbms/include/DB/Common/FileChecker.h
index 194ac1effad..cb4f5493948 100644
--- a/dbms/include/DB/Common/FileChecker.h
+++ b/dbms/include/DB/Common/FileChecker.h
@@ -9,7 +9,7 @@
 #include <DB/Common/escapeForFileName.h>
 
 #include <boost/property_tree/ptree.hpp>
-#include <boost/property_tree/xml_parser.hpp>
+#include <boost/property_tree/json_parser.hpp>
 
 namespace DB
 {
@@ -23,7 +23,7 @@ public:
 		files_info_path(file_info_path_), files_info(), storage(storage_), log(&Logger::get("FileChecker"))
 	{
 		if (Poco::File(files_info_path).exists())
-			boost::property_tree::read_xml(files_info_path, files_info);
+			boost::property_tree::read_json(files_info_path, files_info);
 	}
 
 	void setPath(const std::string & file_info_path_)
@@ -46,7 +46,7 @@ public:
 		saveTree();
 	}
 
-	/// Проверяем файлы, параметры которых указаны в sizes.txt
+	/// Проверяем файлы, параметры которых указаны в sizes.json
 	bool check() const
 	{
 		bool correct = true;
@@ -82,8 +82,7 @@ private:
 
 	void saveTree()
 	{
-		boost::property_tree::write_xml(files_info_path, files_info, std::locale(),
-										boost::property_tree::xml_parser::xml_writer_settings<char>('\t', 1));
+		boost::property_tree::write_json(files_info_path, files_info, std::locale());
 	}
 
 	std::string files_info_path;
diff --git a/dbms/src/Storages/StorageLog.cpp b/dbms/src/Storages/StorageLog.cpp
index e0045e3b72a..6a7cccc7de7 100644
--- a/dbms/src/Storages/StorageLog.cpp
+++ b/dbms/src/Storages/StorageLog.cpp
@@ -411,7 +411,7 @@ void LogBlockOutputStream::writeMarks(MarksForColumns marks)
 
 StorageLog::StorageLog(const std::string & path_, const std::string & name_, NamesAndTypesListPtr columns_, size_t max_compress_block_size_)
 	: path(path_), name(name_), columns(columns_), loaded_marks(false), max_compress_block_size(max_compress_block_size_),
-	file_checker(path + escapeForFileName(name) + '/' + "sizes.txt", *this)
+	file_checker(path + escapeForFileName(name) + '/' + "sizes.json", *this)
 {
 	if (columns->empty())
 		throw Exception("Empty list of columns passed to StorageLog constructor", ErrorCodes::EMPTY_LIST_OF_COLUMNS_PASSED);
@@ -540,7 +540,7 @@ void StorageLog::rename(const String & new_path_to_db, const String & new_databa
 
 	path = new_path_to_db;
 	name = new_table_name;
-	file_checker.setPath(path + escapeForFileName(name) + '/' + "sizes.txt");
+	file_checker.setPath(path + escapeForFileName(name) + '/' + "sizes.json");
 
 	for (Files_t::iterator it = files.begin(); it != files.end(); ++it)
 	{
diff --git a/dbms/src/Storages/StorageTinyLog.cpp b/dbms/src/Storages/StorageTinyLog.cpp
index 0ca5c4fbf3a..d48cbea70e3 100644
--- a/dbms/src/Storages/StorageTinyLog.cpp
+++ b/dbms/src/Storages/StorageTinyLog.cpp
@@ -294,7 +294,7 @@ void TinyLogBlockOutputStream::write(const Block & block)
 StorageTinyLog::StorageTinyLog(const std::string & path_, const std::string & name_, NamesAndTypesListPtr columns_, bool attach, size_t max_compress_block_size_)
 	: path(path_), name(name_), columns(columns_),
 		max_compress_block_size(max_compress_block_size_),
-		file_checker(path + escapeForFileName(name) + '/' + "sizes.txt", *this),
+		file_checker(path + escapeForFileName(name) + '/' + "sizes.json", *this),
 		log(&Logger::get("StorageTinyLog"))
 {
 	if (columns->empty())
@@ -369,7 +369,7 @@ void StorageTinyLog::rename(const String & new_path_to_db, const String & new_da
 
 	path = new_path_to_db;
 	name = new_table_name;
-	file_checker.setPath(path + escapeForFileName(name) + "/" + "sizes.txt");
+	file_checker.setPath(path + escapeForFileName(name) + "/" + "sizes.json");
 
 	for (Files_t::iterator it = files.begin(); it != files.end(); ++it)
 		it->second.data_file = Poco::File(path + escapeForFileName(name) + '/' + Poco::Path(it->second.data_file.path()).getFileName());