diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index 3d4623f05..91ba4a45c 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -46,7 +46,7 @@ uint256 CBlockHeader::GetPoWHash() const
 
     // Merged mining.
     cryptonote::tx_extra_keva_blockhash keva_blockhash;
-    if (!cryptonote::get_keva_blockhash_from_extra(cnHeader.aux_pow->miner_tx.extra, keva_blockhash)) {
+    if (!cryptonote::get_keva_blockhash_from_extra(cnHeader.aux_pow_ptr->miner_tx.extra, keva_blockhash)) {
         return DIFFICULTY_1;
     }
     uint256 actualHash = GetHash();
@@ -55,14 +55,14 @@ uint256 CBlockHeader::GetPoWHash() const
     }
 
     crypto::hash miner_tx_hash;
-    if (!cryptonote::get_transaction_hash(cnHeader.aux_pow->miner_tx, miner_tx_hash)) {
+    if (!cryptonote::get_transaction_hash(cnHeader.aux_pow_ptr->miner_tx, miner_tx_hash)) {
         return DIFFICULTY_1;
     }
 
     crypto::hash aux_blocks_merkle_root;
     crypto::tree_hash_from_branch(
-        reinterpret_cast<const char (*)[32]>(cnHeader.aux_pow->merkle_branch.data()),
-        cnHeader.aux_pow->merkle_branch.size(),
+        reinterpret_cast<const char (*)[32]>(cnHeader.aux_pow_ptr->merkle_branch.data()),
+        cnHeader.aux_pow_ptr->merkle_branch.size(),
         reinterpret_cast<char*>(&miner_tx_hash), 0,
         reinterpret_cast<char*>(&aux_blocks_merkle_root));
 
diff --git a/src/primitives/block.h b/src/primitives/block.h
index ec7f9100b..0fdffded8 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -9,6 +9,7 @@
 #include <primitives/transaction.h>
 #include <serialize.h>
 #include <uint256.h>
+#include <utilstrencodings.h>
 
 #include <cryptonote_basic/cryptonote_format_utils.h>
 
@@ -22,27 +23,6 @@ public:
     // merkel tree whose root is merkle_root.
     std::vector<crypto::hash>  merkle_branch;
 
-    uint256 CheckMerkleBranch (uint256 hash,
-                            const std::vector<uint256>& vMerkleBranch,
-                            int nIndex)
-    {
-        if (nIndex == -1) {
-            return uint256();
-        }
-#if 0
-        for (std::vector<uint256>::const_iterator it(vMerkleBranch.begin());
-            it != vMerkleBranch.end(); ++it) {
-            if (nIndex & 1) {
-                hash = Hash(BEGIN(*it), END(*it), BEGIN(hash), END(hash));
-            } else {
-                hash = Hash(BEGIN(hash), END(hash), BEGIN(*it), END(*it));
-            }
-            nIndex >>= 1;
-        }
-        return hash;
-#endif
-    }
-
     // load
     template <template <bool> class Archive>
     bool do_serialize(Archive<false>& ar)
@@ -82,7 +62,7 @@ private:
     bool is_aux_block;
 
 public:
-    std::unique_ptr<CAuxPow> aux_pow; // It is used only is_aux_block is true.
+    std::shared_ptr<CAuxPow> aux_pow_ptr; // It is used only is_aux_block is true.
 
     CryptoNoteHeader() : is_aux_block(false)
     {
@@ -131,7 +111,7 @@ public:
       memcpy(merkle_root.begin(), &merkle_hash, merkle_root.size());
       VARINT_FIELD(nTxes)
       if (is_aux_block) {
-        aux_pow_ptr = std::make_unique<CAuxPow>();
+        aux_pow_ptr = std::shared_ptr<CAuxPow>(new CAuxPow());
         FIELD(*aux_pow_ptr)
       }
       return true;
@@ -153,7 +133,7 @@ public:
       FIELD(merkle_hash)
       VARINT_FIELD(nTxes)
       if (is_aux_block) {
-        FIELD(*aux_pow)
+        FIELD(*aux_pow_ptr)
       }
       return true;
     }
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 07bed95b6..5796433a2 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -621,7 +621,7 @@ static uint256 CryptoHashToUint256(const crypto::hash& hash)
 // Cryptonote RPC call, only one parameter allowed.
 UniValue submitblock(const JSONRPCRequest& request)
 {
-    if (request.fHelp || request.params.size() < 2) {
+    if (request.fHelp || request.params.size() > 2 || request.params.size() < 1) {
         throw std::runtime_error(
             "submitblock \"hexdata\"\n"
             "\nAttempts to submit new block to network.\n"
@@ -637,7 +637,7 @@ UniValue submitblock(const JSONRPCRequest& request)
         );
     }
 
-    std::unique_ptr<CAuxPow> auxPow = std::make_unique<CAuxPow>();
+    std::shared_ptr<CAuxPow> auxPow;
     bool isAuxPow = false;
     if (request.params.size() == 2) {
         if (request.params[1].getType() != UniValue::VSTR) {
@@ -647,6 +647,7 @@ UniValue submitblock(const JSONRPCRequest& request)
         ss << request.params[1].get_str();
         // load
         binary_archive<false> ba(ss);
+        auxPow = std::shared_ptr<CAuxPow>(new CAuxPow());
         isAuxPow = ::serialization::serialize(ba, *auxPow);
     }
 
@@ -698,7 +699,7 @@ UniValue submitblock(const JSONRPCRequest& request)
 
     block.cnHeader.SetAuxBlock(isAuxPow);
     if (isAuxPow) {
-        block.cnHeader.aux_pow = std::move(auxPow);
+        block.cnHeader.aux_pow_ptr = auxPow;
     }
 
     // TODO: fix the return message.
@@ -954,7 +955,7 @@ static const CRPCCommand commands[] =
     { "mining",             "getmininginfo",          &getmininginfo,          {} },
     { "mining",             "prioritisetransaction",  &prioritisetransaction,  {"txid","dummy","fee_delta"} },
     { "mining",             "getblocktemplate",       &getblocktemplate,       {"reserve_size", "wallet_address", "is_aux_block"} },
-    { "mining",             "submitblock",            &submitblock,            {"hexdata","auxpow"} },
+    { "mining",             "submitblock",            &submitblock,            {"hexdata", "auxpow"} },
 
 
     { "generating",         "generatetoaddress",      &generatetoaddress,      {"nblocks","address","maxtries"} },