diff --git a/src/currency_core/blockchain_storage.cpp b/src/currency_core/blockchain_storage.cpp
index 2c064da2..169868f9 100644
--- a/src/currency_core/blockchain_storage.cpp
+++ b/src/currency_core/blockchain_storage.cpp
@@ -58,7 +58,7 @@ using namespace currency;
 #define BLOCKCHAIN_STORAGE_OPTIONS_ID_CURRENT_BLOCK_CUMUL_SZ_LIMIT          0
 #define BLOCKCHAIN_STORAGE_OPTIONS_ID_CURRENT_PRUNED_RS_HEIGHT              1
 #define BLOCKCHAIN_STORAGE_OPTIONS_ID_LAST_WORKED_VERSION                   2
-#define BLOCKCHAIN_STORAGE_OPTIONS_ID_STORAGE_MAJOR_COMPATIBILITY_VERSION   3 //mismatch here means full resync
+#define BLOCKCHAIN_STORAGE_OPTIONS_ID_STORAGE_MAJOR_COMPATIBILITY_VERSION   4 //mismatch here means full resync
 #define BLOCKCHAIN_STORAGE_OPTIONS_ID_STORAGE_MINOR_COMPATIBILITY_VERSION   4 //mismatch here means some reinitializations
 
 #define TARGETDATA_CACHE_SIZE                          DIFFICULTY_WINDOW + 10
diff --git a/tests/core_tests/hard_fork_1_bad_pos_source.cpp b/tests/core_tests/hard_fork_1_bad_pos_source.cpp
new file mode 100644
index 00000000..1fd43a0c
--- /dev/null
+++ b/tests/core_tests/hard_fork_1_bad_pos_source.cpp
@@ -0,0 +1,93 @@
+// Copyright (c) 2014-2018 Zano Project
+// Copyright (c) 2014-2018 The Louisdor Project
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "chaingen.h"
+#include "pos_validation.h"
+#include "tx_builder.h"
+#include "hard_fork_1_bad_pos_source.h"
+#include "random_helper.h"
+
+using namespace epee;
+using namespace crypto;
+using namespace currency;
+
+hard_fork_1_bad_pos_source::hard_fork_1_bad_pos_source()
+{
+  REGISTER_CALLBACK_METHOD(hard_fork_1_bad_pos_source, c1);
+  REGISTER_CALLBACK_METHOD(hard_fork_1_bad_pos_source, configure_core);
+}
+
+bool hard_fork_1_bad_pos_source::generate(std::vector<test_event_entry>& events) const
+{
+  random_state_test_restorer::reset_random();
+
+  GENERATE_ACCOUNT(preminer_acc);
+  GENERATE_ACCOUNT(miner_acc);
+  GENERATE_ACCOUNT(pos_miner_acc_before_pow);
+  GENERATE_ACCOUNT(pos_miner_acc_after_pow);
+  m_accounts.push_back(miner_acc);
+  m_accounts.push_back(pos_miner_acc_before_pow);
+  m_accounts.push_back(pos_miner_acc_after_pow);
+  std::list<account_base> miner_acc_lst(1, miner_acc);
+
+  MAKE_GENESIS_BLOCK(events, blk_0, preminer_acc, 1564434616);
+  generator.set_hardfork_height(get_hardfork_height());
+
+  DO_CALLBACK(events, "configure_core");
+  REWIND_BLOCKS_N_WITH_TIME(events, blk_0r, blk_0, miner_acc, CURRENCY_MINED_MONEY_UNLOCK_WINDOW + 5);
+  generator.set_pos_to_low_timestamp(true);
+  MAKE_TX(events, tx_1, miner_acc, pos_miner_acc_before_pow, 1000000000000, blk_0r);
+  MAKE_NEXT_BLOCK_TX1(events, blk_pow_tx1, blk_0r, miner_acc, tx_1);
+  MAKE_TX(events, tx_2, preminer_acc, pos_miner_acc_after_pow, 1000000000000, blk_pow_tx1);
+  MAKE_NEXT_POS_BLOCK_TX1(events, blk_pos_tx2, blk_pow_tx1, miner_acc, miner_acc_lst, tx_2);
+
+  block last_block = blk_pos_tx2;
+  for (size_t i = 0; i != CURRENCY_MINED_MONEY_UNLOCK_WINDOW; i++)
+  {
+    MAKE_NEXT_POS_BLOCK(events, next_blk_pos, last_block, miner_acc, miner_acc_lst);
+    events.push_back(event_core_time(next_blk_pos.timestamp - 10));
+    last_block = next_blk_pos;
+  }
+  
+  std::list<currency::account_base> accounts_before_pow;
+  accounts_before_pow.push_back(pos_miner_acc_before_pow);
+  //let's try to mint PoW block from account 
+  MAKE_NEXT_POS_BLOCK(events, next_blk_pos2, last_block, miner_acc, accounts_before_pow);
+
+  std::list<currency::account_base> accounts_after_pow;
+  accounts_after_pow.push_back(pos_miner_acc_after_pow);
+  //let's try to mint PoW block from account 
+  generator.set_ignore_last_pow_in_wallets(true);
+  DO_CALLBACK(events, "mark_invalid_block");
+  MAKE_NEXT_POS_BLOCK(events, next_blk_pos3, next_blk_pos2, miner_acc, accounts_after_pow);
+
+  DO_CALLBACK(events, "c1");
+  return true;
+}
+
+bool hard_fork_1_bad_pos_source::configure_core(currency::core& c, size_t ev_index, const std::vector<test_event_entry>& events)
+{
+  currency::core_runtime_config pc = c.get_blockchain_storage().get_core_runtime_config();
+  pc.min_coinstake_age = TESTS_POS_CONFIG_MIN_COINSTAKE_AGE; //four blocks
+  pc.pos_minimum_heigh = TESTS_POS_CONFIG_POS_MINIMUM_HEIGH; //four blocks
+  pc.hard_fork1_starts_after_height = get_hardfork_height();
+
+  c.get_blockchain_storage().set_core_runtime_config(pc);
+  return true;
+}
+
+bool hard_fork_1_bad_pos_source::c1(currency::core& c, size_t ev_index, const std::vector<test_event_entry>& events)
+{
+  
+  uint64_t h = c.get_blockchain_storage().get_current_blockchain_size();
+  CHECK_AND_ASSERT_MES(h == 29, false, "locked pos block is not accepted");
+  return true;
+}
+
+uint64_t hard_fork_1_bad_pos_source::get_hardfork_height()const
+{
+  return 10; 
+}
+
diff --git a/tests/core_tests/hard_fork_1_bad_pos_source.h b/tests/core_tests/hard_fork_1_bad_pos_source.h
new file mode 100644
index 00000000..e59adfa3
--- /dev/null
+++ b/tests/core_tests/hard_fork_1_bad_pos_source.h
@@ -0,0 +1,18 @@
+// Copyright (c) 2014-2018 Zano Project
+// Copyright (c) 2014-2018 The Louisdor Project
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#pragma once 
+#include "chaingen.h"
+#include "wallet_tests_basic.h"
+
+
+struct hard_fork_1_bad_pos_source : public wallet_test
+{
+  hard_fork_1_bad_pos_source();
+  bool generate(std::vector<test_event_entry>& events) const;
+  bool configure_core(currency::core& c, size_t ev_index, const std::vector<test_event_entry>& events);
+  virtual bool c1(currency::core& c, size_t ev_index, const std::vector<test_event_entry>& events);
+  virtual uint64_t get_hardfork_height()const;
+};