diff --git a/tests/core_tests/chaingen.cpp b/tests/core_tests/chaingen.cpp
index 272fd9e0..0b12b543 100644
--- a/tests/core_tests/chaingen.cpp
+++ b/tests/core_tests/chaingen.cpp
@@ -1621,9 +1621,14 @@ void get_confirmed_txs(const std::vector<currency::block>& blockchain, const map
 
 bool find_block_chain(const std::vector<test_event_entry>& events, std::vector<currency::block>& blockchain, map_hash2tx_t& mtx, const crypto::hash& head)
 {
+  size_t invalid_tx_index     = UINT64_MAX;
+  size_t invalid_block_index  = UINT64_MAX;
   std::unordered_map<crypto::hash, const block*> block_index;
   for(size_t i = 0, sz = events.size(); i < sz; ++i)
   {
+    if (invalid_tx_index == i || invalid_block_index == i)
+      continue;
+
     const test_event_entry& ev = events[i];
     if (typeid(currency::block) == ev.type())
     {
@@ -1643,6 +1648,14 @@ bool find_block_chain(const std::vector<test_event_entry>& events, std::vector<c
       const transaction& tx = boost::get<transaction>(ev);
       mtx[get_transaction_hash(tx)] = &tx;
     }
+    else if (test_chain_unit_enchanced::is_event_mark_invalid_block(ev))
+    {
+      invalid_block_index = i + 1;
+    }
+    else if (test_chain_unit_enchanced::is_event_mark_invalid_tx(ev))
+    {
+      invalid_tx_index = i + 1;
+    }
   }
 
   bool b_success = false;
diff --git a/tests/core_tests/chaingen.h b/tests/core_tests/chaingen.h
index 2e015a28..b092204e 100644
--- a/tests/core_tests/chaingen.h
+++ b/tests/core_tests/chaingen.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2014-2018 Zano Project
+// Copyright (c) 2014-2022 Zano Project
 // Copyright (c) 2014-2018 The Louisdor Project
 // Copyright (c) 2012-2013 The Cryptonote developers
 // Distributed under the MIT/X11 software license, see the accompanying
@@ -319,6 +319,22 @@ public:
   bool check_hardfork_active(currency::core& c, size_t ev_index, const std::vector<test_event_entry>& events);
 
 
+  static bool is_event_mark_invalid_block(const test_event_entry& ev)
+  {
+    if (typeid(callback_entry) != ev.type())
+      return false;
+    const callback_entry& ce = boost::get<callback_entry>(ev);
+    return ce.callback_name == "mark_invalid_block";
+  }
+
+  static bool is_event_mark_invalid_tx(const test_event_entry& ev)
+  {
+    if (typeid(callback_entry) != ev.type())
+      return false;
+    const callback_entry& ce = boost::get<callback_entry>(ev);
+    return ce.callback_name == "mark_invalid_tx";
+  }
+
 
 protected:
   struct params_top_block