diff --git a/contrib/epee/include/storages/portable_storage_val_converters.h b/contrib/epee/include/storages/portable_storage_val_converters.h
index caf7a322..f2c49f0e 100644
--- a/contrib/epee/include/storages/portable_storage_val_converters.h
+++ b/contrib/epee/include/storages/portable_storage_val_converters.h
@@ -129,7 +129,20 @@ POP_VS_WARNINGS
     template<typename from_type, typename to_type>
     struct convert_to_integral<from_type, to_type, false>
     {
-      static void convert(const from_type& from, to_type& to)
+      static void convert(const const std::string& from, uint64_t& to)
+      {
+        //attempt to convert string to unsigned int
+        try
+        {
+          to = std::stoull(from);
+        }catch(...)
+        {
+          ASSERT_AND_THROW_WRONG_CONVERSION();
+        }
+      }
+
+      template<typename from_type_t, typename to_type_t>
+      static void convert(const from_type_t& from, to_type_t& to)
       {
         ASSERT_AND_THROW_WRONG_CONVERSION();
       }
diff --git a/tests/functional_tests/main.cpp b/tests/functional_tests/main.cpp
index b275bd4a..d211a3bc 100644
--- a/tests/functional_tests/main.cpp
+++ b/tests/functional_tests/main.cpp
@@ -109,7 +109,7 @@ int main(int argc, char* argv[])
   command_line::add_arg(desc_options, arg_crypto_tests);
   
   
-  test_serialization();
+  test_serialization2();
 
   po::variables_map vm;
   bool r = command_line::handle_error_helper(desc_options, [&]()
diff --git a/tests/functional_tests/transactions_flow_test.cpp b/tests/functional_tests/transactions_flow_test.cpp
index be76d998..b6128929 100644
--- a/tests/functional_tests/transactions_flow_test.cpp
+++ b/tests/functional_tests/transactions_flow_test.cpp
@@ -386,6 +386,26 @@ bool test_serialization()
   return true;
 }
 
+
+struct test_serialization_2
+{
+  uint64_t var1;
+  uint64_t var2;
+  BEGIN_KV_SERIALIZE_MAP()
+    KV_SERIALIZE(var1)
+    KV_SERIALIZE(var2)
+  END_KV_SERIALIZE_MAP()
+};
+
+bool test_serialization2()
+{
+  test_serialization_2 ee = {};
+  std::string json_buf = "{\"var1\": 111, \"var2\": \"222\"}";
+  epee::serialization::load_t_from_json(ee, json_buf);
+  std::string json_buf2 = epee::serialization::store_t_to_json(ee);
+  return true;
+}
+
 bool transactions_flow_test(
   std::wstring path_source_wallet, std::string source_wallet_pass,
   std::wstring path_terget_wallet, std::string target_wallet_pass,
diff --git a/tests/functional_tests/transactions_flow_test.h b/tests/functional_tests/transactions_flow_test.h
index 7f7aa528..ac023efc 100644
--- a/tests/functional_tests/transactions_flow_test.h
+++ b/tests/functional_tests/transactions_flow_test.h
@@ -16,4 +16,5 @@ bool transactions_flow_test(
   std::string& daemon_addr_a,
   std::string& daemon_addr_b,
   size_t mix_in_factor, size_t action = TRANSACTIONS_FLOW_TESTACTION_DEFAULT, uint64_t max_tx_in_pool = 10000);
-bool test_serialization();
\ No newline at end of file
+bool test_serialization();
+bool test_serialization2();
\ No newline at end of file