diff --git a/src/currency_core/currency_format_utils.cpp b/src/currency_core/currency_format_utils.cpp
index c1c69f25..17d411d2 100644
--- a/src/currency_core/currency_format_utils.cpp
+++ b/src/currency_core/currency_format_utils.cpp
@@ -216,7 +216,7 @@ namespace currency
       decompose_amount_into_digits(block_reward, DEFAULT_DUST_THRESHOLD,
         [&out_amounts](uint64_t a_chunk) { out_amounts.push_back(a_chunk); },
         [&out_amounts](uint64_t a_dust) { out_amounts.push_back(a_dust); });
-      CHECK_AND_ASSERT_MES(1 <= max_outs, false, "max_out must be non-zero");
+      CHECK_AND_ASSERT_MES(2 <= max_outs, false, "max_out must be greather than 1");
       while (max_outs < out_amounts.size())
       {
         out_amounts[out_amounts.size() - 2] += out_amounts.back();
@@ -271,26 +271,16 @@ namespace currency
     {
       if (tx.version > TRANSACTION_VERSION_PRE_HF4 /* && stake is zarcanum */)
       {
-        // TODO: add Zarcanum part
-        //txin_zc_input stake_input = AUTO_VAL_INIT(stake_input);
-        //stake_input.key_offsets.push_back(pe.g_index);
-        //stake_input.k_image = pe.keyimage;
+        // just placeholders, they will be filled in wallet2::prepare_and_sign_pos_block()
         tx.vin.emplace_back(std::move(txin_zc_input()));
-        //reserve place for ring signature
         tx.signatures.emplace_back(std::move(zarcanum_sig()));
       }
       else
       {
         // old fashioned non-hidden amount direct spend PoS scheme
-        txin_to_key stake_input;
-        stake_input.amount = pe.amount;
-        stake_input.key_offsets.push_back(pe.g_index);
-        stake_input.k_image = pe.keyimage;
-        tx.vin.push_back(stake_input);
-        //reserve place for ring signature
-        NLSAG_sig nlsag;
-        nlsag.s.resize(stake_input.key_offsets.size());
-        tx.signatures.push_back(nlsag); // consider using emplace_back and avoid copying
+        // just placeholders, they will be filled in wallet2::prepare_and_sign_pos_block()
+        tx.vin.emplace_back(std::move(txin_to_key()));
+        tx.signatures.emplace_back(std::move(NLSAG_sig()));
       }
     }
 
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index ba0f215a..d90e1554 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -3666,13 +3666,20 @@ bool wallet2::prepare_and_sign_pos_block(const mining_context& cxt, currency::bl
     // old PoS with non-hidden amounts
     WLT_CHECK_AND_ASSERT_MES(b.miner_tx.vin[0].type() == typeid(currency::txin_gen), false, "Wrong input 0 type in transaction: " << b.miner_tx.vin[0].type().name());
     WLT_CHECK_AND_ASSERT_MES(b.miner_tx.vin[1].type() == typeid(currency::txin_to_key), false, "Wrong input 1 type in transaction: " << b.miner_tx.vin[1].type().name());
-    auto& txin = boost::get<currency::txin_to_key>(b.miner_tx.vin[1]);
-    txin.k_image = pe.keyimage;
+    WLT_CHECK_AND_ASSERT_MES(b.miner_tx.signatures.size() == 1 && b.miner_tx.signatures[0].type() == typeid(NLSAG_sig), false, "wrong sig prepared in a PoS block");
+    WLT_CHECK_AND_ASSERT_MES(stake_out_v.type() == typeid(tx_out_bare), false, "unexpected stake output type: " << stake_out_v.type().name() << ", expected: tx_out_bare");
+    const tx_out_bare& stake_out = boost::get<tx_out_bare>(stake_out_v);
+    WLT_CHECK_AND_ASSERT_MES(stake_out.target.type() == typeid(txout_to_key), false, "unexpected stake output target type: " << stake_out.target.type().name() << ", expected: txout_to_key");
+    
 
-    WLT_CHECK_AND_ASSERT_MES(b.miner_tx.signatures.size() == 1 &&
-      b.miner_tx.signatures[0].type() == typeid(NLSAG_sig) &&
-      boost::get<NLSAG_sig>(b.miner_tx.signatures[0]).s.size() == txin.key_offsets.size(),
-      false, "Wrong signatures amount in coinbase transacton");
+    NLSAG_sig& sig = boost::get<NLSAG_sig>(b.miner_tx.signatures[0]);
+    txin_to_key& stake_input = boost::get<txin_to_key>(b.miner_tx.vin[1]);
+    const txout_to_key& stake_out_target = boost::get<txout_to_key>(stake_out.target);
+    
+    stake_input.k_image = pe.keyimage;
+    stake_input.amount = pe.amount;
+    stake_input.key_offsets.push_back(pe.g_index);
+    sig.s.resize(1);
 
     //derive secret key
     crypto::key_derivation pos_coin_derivation = AUTO_VAL_INIT(pos_coin_derivation);
@@ -3693,21 +3700,19 @@ bool wallet2::prepare_and_sign_pos_block(const mining_context& cxt, currency::bl
 
     // get stake output pub key (stealth address) for ring signature generation
     std::vector<const crypto::public_key*> keys_ptrs;
-    TRY_ENTRY()
-      keys_ptrs.push_back(&boost::get<currency::txout_to_key>(boost::get<tx_out_bare>(stake_out_v).target).key);
-    CATCH_ENTRY_CUSTOM("wallet2::prepare_and_sign_pos_block", { LOG_PRINT_RED_L0("unable to get output's pub key because of the exception"); }, false);
+    keys_ptrs.push_back(&stake_out_target.key);
 
     crypto::generate_ring_signature(block_hash,
-      txin.k_image,
+      stake_input.k_image,
       keys_ptrs,
       derived_secret_ephemeral_key,
       0,
-      &boost::get<NLSAG_sig>(b.miner_tx.signatures[0]).s[0]);
+      &sig.s[0]);
 
-    WLT_LOG_L4("GENERATED RING SIGNATURE: block_id " << block_hash
-      << "txin.k_image" << txin.k_image
+    WLT_LOG_L4("GENERATED RING SIGNATURE for PoS block coinbase: block_id " << block_hash
+      << "txin.k_image" << stake_input.k_image
       << "key_ptr:" << *keys_ptrs[0]
-      << "signature:" << boost::get<NLSAG_sig>(b.miner_tx.signatures[0]).s);
+      << "signature:" << sig.s);
 
     return true;
   }