diff --git a/src/currency_core/blockchain_storage.cpp b/src/currency_core/blockchain_storage.cpp
index 0388b733..59b0dd16 100644
--- a/src/currency_core/blockchain_storage.cpp
+++ b/src/currency_core/blockchain_storage.cpp
@@ -1322,17 +1322,10 @@ bool blockchain_storage::prevalidate_miner_transaction(const block& b, uint64_t
 
   if (is_hardfork_active(ZANO_HARDFORK_04_ZARCANUM)) // TODO @#@# consider moving to validate_tx_for_hardfork_specific_terms
   {
-    if (pos)
-    {
-      CHECK_AND_ASSERT_MES(b.miner_tx.proofs.size() == 1, false, "coinbase transaction has incorrect number of proofs (" << b.miner_tx.proofs.size() << "), expected 2");
-      CHECK_AND_ASSERT_MES(b.miner_tx.proofs[0].type() == typeid(zc_outs_range_proof), false, "coinbase transaction has incorrect type of proof #0 (expected: zc_outs_range_proof)");
-    }
-    else
-    {
-      CHECK_AND_ASSERT_MES(b.miner_tx.proofs.size() == 2, false, "coinbase transaction has incorrect number of proofs (" << b.miner_tx.proofs.size() << "), expected 2");
-      CHECK_AND_ASSERT_MES(b.miner_tx.proofs[0].type() == typeid(zc_outs_range_proof), false, "coinbase transaction has incorrect type of proof #0 (expected: zc_outs_range_proof)");
-      CHECK_AND_ASSERT_MES(b.miner_tx.proofs[1].type() == typeid(zc_balance_proof), false, "coinbase transaction has incorrect type of proof #1 (expected: zc_balance_proof)");
-    }
+    CHECK_AND_ASSERT_MES(b.miner_tx.attachment.empty(), false, "coinbase transaction has attachments; attachments are not allowed for coinbase transactions.");
+    CHECK_AND_ASSERT_MES(b.miner_tx.proofs.size() == 2, false, "coinbase transaction has incorrect number of proofs (" << b.miner_tx.proofs.size() << "), expected 2");
+    CHECK_AND_ASSERT_MES(b.miner_tx.proofs[0].type() == typeid(zc_outs_range_proof), false, "coinbase transaction has incorrect type of proof #0 (expected: zc_outs_range_proof)");
+    CHECK_AND_ASSERT_MES(b.miner_tx.proofs[1].type() == typeid(zc_balance_proof), false, "coinbase transaction has incorrect type of proof #1 (expected: zc_balance_proof)");
   }
   else
   {
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 19d8758e..f04ac527 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -3831,7 +3831,7 @@ bool wallet2::is_in_hardfork_zone(uint64_t hardfork_index) const
   return m_core_runtime_config.is_hardfork_active_for_height(hardfork_index, get_blockchain_current_size());
 }
 //----------------------------------------------------------------------------------------------------
-bool wallet2::prepare_and_sign_pos_block(const mining_context& cxt, currency::block& b, const pos_entry& pe, const currency::outputs_generation_context& miner_tx_ogc) const
+bool wallet2::prepare_and_sign_pos_block(const mining_context& cxt, currency::block& b, const pos_entry& pe, currency::outputs_generation_context& miner_tx_ogc) const
 {
   bool r = false;
   WLT_CHECK_AND_ASSERT_MES(pe.wallet_index < m_transfers.size(), false, "invalid pe.wallet_index: " << pe.wallet_index);
@@ -3987,6 +3987,9 @@ bool wallet2::prepare_and_sign_pos_block(const mining_context& cxt, currency::bl
     static_cast<crypto::zarcanum_proof&>(sig), &err);
   WLT_CHECK_AND_ASSERT_MES(r, false, "zarcanum_generate_proof failed, err: " << (int)err);
 
+  // TODO @#@# [architecture] the same value is calculated in zarcanum_generate_proof(), consider an impovement 
+  miner_tx_ogc.pseudo_out_amount_commitments_sum += cxt.stake_amount * currency::native_coin_asset_id_pt + pseudo_out_amount_blinding_mask * crypto::c_point_G;
+
   //
   // The miner tx prefix should be sealed by now, and the tx hash should be defined.
   // Any changes made below should only affect the signatures/proofs and should not impact the prefix hash calculation.   
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 1b2d436c..e5799fcd 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -856,7 +856,7 @@ namespace tools
     //next functions in public area only becausce of test_generator
     //TODO: Need refactoring - remove it back to private zone 
     void set_genesis(const crypto::hash& genesis_hash);
-    bool prepare_and_sign_pos_block(const mining_context& cxt, currency::block& b, const currency::pos_entry& pe, const currency::outputs_generation_context& miner_tx_ogc) const;
+    bool prepare_and_sign_pos_block(const mining_context& cxt, currency::block& b, const currency::pos_entry& pe, currency::outputs_generation_context& miner_tx_ogc) const;
     void process_new_blockchain_entry(const currency::block& b, 
       const currency::block_direct_data_entry& bche, 
       const crypto::hash& bl_id,
diff --git a/tests/core_tests/chaingen.cpp b/tests/core_tests/chaingen.cpp
index 1c19c459..2615a5ef 100644
--- a/tests/core_tests/chaingen.cpp
+++ b/tests/core_tests/chaingen.cpp
@@ -362,7 +362,7 @@ bool test_generator::construct_block(currency::block& blk,
 bool test_generator::sign_block(const tools::wallet2::mining_context& mining_context,
                                 const pos_entry& pe,
                                 const tools::wallet2& w,
-                                const outputs_generation_context& miner_tx_ogc,
+                                outputs_generation_context& miner_tx_ogc,
                                 currency::block& b)
 {
   bool r = w.prepare_and_sign_pos_block(mining_context, b, pe, miner_tx_ogc);
diff --git a/tests/core_tests/chaingen.h b/tests/core_tests/chaingen.h
index d8905f6c..605f7fe0 100644
--- a/tests/core_tests/chaingen.h
+++ b/tests/core_tests/chaingen.h
@@ -467,7 +467,7 @@ public:
   bool sign_block(const tools::wallet2::mining_context& mining_context,
                   const currency::pos_entry& pe,
                   const tools::wallet2& w,
-                  const currency::outputs_generation_context& miner_tx_ogc,
+                  currency::outputs_generation_context& miner_tx_ogc,
                   currency::block& b);
   
   /*bool get_output_details_by_global_index(const test_generator::blockchain_vector& blck_chain,