diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index 98c53890e..cfe3b5441 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -60,6 +60,8 @@ DISABLE_VS_WARNINGS(4355)
 
 #define MERROR_VER(x) MCERROR("verify", x)
 
+#define BAD_SEMANTICS_TXES_MAX_SIZE 100
+
 namespace cryptonote
 {
 
@@ -496,11 +498,14 @@ namespace cryptonote
     }
     //std::cout << "!"<< tx.vin.size() << std::endl;
 
-    if (bad_semantics_txes.find(tx_hash) != bad_semantics_txes.end())
+    for (int idx = 0; idx < 2; ++idx)
     {
-      LOG_PRINT_L1("Transaction already seen with bad semantics, rejected");
-      tvc.m_verifivation_failed = true;
-      return false;
+      if (bad_semantics_txes[idx].find(tx_hash) != bad_semantics_txes[idx].end())
+      {
+        LOG_PRINT_L1("Transaction already seen with bad semantics, rejected");
+        tvc.m_verifivation_failed = true;
+        return false;
+      }
     }
 
     uint8_t version = m_blockchain_storage.get_current_hard_fork_version();
@@ -551,8 +556,13 @@ namespace cryptonote
     if(!check_tx_semantic(tx, keeped_by_block))
     {
       LOG_PRINT_L1("WRONG TRANSACTION BLOB, Failed to check tx " << tx_hash << " semantic, rejected");
-      bad_semantics_txes.insert(tx_hash);
       tvc.m_verifivation_failed = true;
+      bad_semantics_txes[0].insert(tx_hash);
+      if (bad_semantics_txes[0].size() >= BAD_SEMANTICS_TXES_MAX_SIZE)
+      {
+        std::swap(bad_semantics_txes[0], bad_semantics_txes[1]);
+        bad_semantics_txes[0].clear();
+      }
       return false;
     }
 
diff --git a/src/cryptonote_core/cryptonote_core.h b/src/cryptonote_core/cryptonote_core.h
index 114e8393e..7323bef29 100644
--- a/src/cryptonote_core/cryptonote_core.h
+++ b/src/cryptonote_core/cryptonote_core.h
@@ -818,7 +818,6 @@ namespace cryptonote
      epee::math_helper::once_a_time_seconds<60*2, false> m_txpool_auto_relayer; //!< interval for checking re-relaying txpool transactions
      epee::math_helper::once_a_time_seconds<60*60*12, true> m_check_updates_interval; //!< interval for checking for new versions
 
-     friend class tx_validate_inputs;
      std::atomic<bool> m_starter_message_showed; //!< has the "daemon will sync now" message been shown?
 
      uint64_t m_target_blockchain_height; //!< blockchain height target
@@ -833,13 +832,11 @@ namespace cryptonote
 
      std::atomic_flag m_checkpoints_updating; //!< set if checkpoints are currently updating to avoid multiple threads attempting to update at once
 
-     boost::interprocess::file_lock db_lock; //!< a lock object for a file lock in the db directory
-
      size_t block_sync_size;
 
      time_t start_time;
 
-     std::unordered_set<crypto::hash> bad_semantics_txes;
+     std::unordered_set<crypto::hash> bad_semantics_txes[2];
 
      enum {
        UPDATES_DISABLED,