diff --git a/geocoder/hierarchy_reader.cpp b/geocoder/hierarchy_reader.cpp
index ecc54efd9d..ce9269309e 100644
--- a/geocoder/hierarchy_reader.cpp
+++ b/geocoder/hierarchy_reader.cpp
@@ -71,6 +71,7 @@ Hierarchy HierarchyReader::Read(unsigned int readersCount)
     while (!m_eof && tasks.size() <= 2 * readersCount)
       tasks.emplace_back(threadPool.Submit([&] { return ReadEntries(kReadBlockLineCount); }));
 
+    CHECK(!tasks.empty(), ());
     auto & task = tasks.front();
     auto taskResult = task.get();
     tasks.pop_front();
@@ -192,14 +193,16 @@ HierarchyReader::ParsingResult HierarchyReader::DeserializeEntries(
     entries.push_back(move(entry));
   }
 
-  return {std::move(entries), std::move(stats)};
+  return {move(entries), move(stats)};
 }
 
+// static
 bool HierarchyReader::DeserializeId(string const & str, uint64_t & id)
 {
   return strings::to_uint64(str, id, 16 /* base */);
 }
 
+// static
 string HierarchyReader::SerializeId(uint64_t id)
 {
   stringstream s;
diff --git a/geocoder/hierarchy_reader.hpp b/geocoder/hierarchy_reader.hpp
index b809961d52..9f1bd8b2b7 100644
--- a/geocoder/hierarchy_reader.hpp
+++ b/geocoder/hierarchy_reader.hpp
@@ -39,8 +39,8 @@ private:
   ParsingResult ReadEntries(size_t count);
   ParsingResult DeserializeEntries(std::vector<std::string> const & linesBuffer,
                                     std::size_t const bufferSize);
-  bool DeserializeId(std::string const & str, uint64_t & id);
-  std::string SerializeId(uint64_t id);
+  static bool DeserializeId(std::string const & str, uint64_t & id);
+  static std::string SerializeId(uint64_t id);
 
   void CheckDuplicateOsmIds(std::vector<Entry> const & entries, ParsingStats & stats);