diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index d00e3773c7..108f8aa11f 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -374,7 +374,7 @@ static UniValue waitforblock(const JSONRPCRequest& request)
     }.Check(request);
     int timeout = 0;
 
-    uint256 hash = uint256S(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
     if (!request.params[1].isNull())
         timeout = request.params[1].get_int();
@@ -634,7 +634,7 @@ static UniValue getmempoolancestors(const JSONRPCRequest& request)
     if (!request.params[1].isNull())
         fVerbose = request.params[1].get_bool();
 
-    uint256 hash = ParseHashV(request.params[0], "parameter 1");
+    uint256 hash(ParseHashV(request.params[0], "parameter 1"));
 
     const CTxMemPool& mempool = EnsureMemPool(request.context);
     LOCK(mempool.cs);
@@ -698,7 +698,7 @@ static UniValue getmempooldescendants(const JSONRPCRequest& request)
     if (!request.params[1].isNull())
         fVerbose = request.params[1].get_bool();
 
-    uint256 hash = ParseHashV(request.params[0], "parameter 1");
+    uint256 hash(ParseHashV(request.params[0], "parameter 1"));
 
     const CTxMemPool& mempool = EnsureMemPool(request.context);
     LOCK(mempool.cs);
@@ -749,7 +749,7 @@ static UniValue getmempoolentry(const JSONRPCRequest& request)
         },
     }.Check(request);
 
-    uint256 hash = ParseHashV(request.params[0], "parameter 1");
+    uint256 hash(ParseHashV(request.params[0], "parameter 1"));
 
     const CTxMemPool& mempool = EnsureMemPool(request.context);
     LOCK(mempool.cs);
@@ -862,8 +862,7 @@ static UniValue getblockheader(const JSONRPCRequest& request)
         },
     }.Check(request);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "hash"));
 
     bool fVerbose = true;
     if (!request.params[1].isNull())
@@ -936,8 +935,7 @@ static UniValue getblockheaders(const JSONRPCRequest& request)
         },
     }.Check(request);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
     const CBlockIndex* pblockindex;
     const CBlockIndex* tip;
@@ -1048,8 +1046,7 @@ static UniValue getmerkleblocks(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Filter is not within size constraints");
     }
 
-    std::string strHash = request.params[1].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[1], "blockhash"));
 
     const CBlockIndex* pblockindex = g_chainman.m_blockman.LookupBlockIndex(hash);
     if (!pblockindex) {
@@ -1154,8 +1151,7 @@ static UniValue getblock(const JSONRPCRequest& request)
                 },
     }.Check(request);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
     int verbosity = 1;
     if (!request.params[1].isNull()) {
@@ -1356,8 +1352,7 @@ static UniValue gettxout(const JSONRPCRequest& request)
 
     UniValue ret(UniValue::VOBJ);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "txid"));
     int n = request.params[1].get_int();
     COutPoint out(hash, n);
     bool fMempool = true;
@@ -1805,8 +1800,7 @@ static UniValue preciousblock(const JSONRPCRequest& request)
         },
     }.Check(request);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
     CBlockIndex* pblockindex;
 
     {
@@ -1841,8 +1835,7 @@ static UniValue invalidateblock(const JSONRPCRequest& request)
         },
     }.Check(request);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
     CValidationState state;
 
     CBlockIndex* pblockindex;
@@ -1881,8 +1874,7 @@ static UniValue reconsiderblock(const JSONRPCRequest& request)
         },
     }.Check(request);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
     {
         LOCK(cs_main);
@@ -1937,7 +1929,7 @@ static UniValue getchaintxstats(const JSONRPCRequest& request)
         LOCK(cs_main);
         pindex = ::ChainActive().Tip();
     } else {
-        uint256 hash = uint256S(request.params[1].get_str());
+        uint256 hash(ParseHashV(request.params[1], "blockhash"));
         LOCK(cs_main);
         pindex = g_chainman.m_blockman.LookupBlockIndex(hash);
         if (!pindex) {
@@ -2114,8 +2106,7 @@ static UniValue getblockstats(const JSONRPCRequest& request)
 
         pindex = ::ChainActive()[height];
     } else {
-        const uint256 hash = ParseHashV(request.params[0], "parameter 1");
-
+        const uint256 hash(ParseHashV(request.params[0], "hash_or_height"));
         pindex = g_chainman.m_blockman.LookupBlockIndex(hash);
         if (!pindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
@@ -2307,8 +2298,7 @@ static UniValue getspecialtxes(const JSONRPCRequest& request)
 
     LOCK(cs_main);
 
-    std::string strHash = request.params[0].get_str();
-    uint256 hash(uint256S(strHash));
+    uint256 hash(ParseHashV(request.params[0], "blockhash"));
 
     int nTxType = -1;
     if (!request.params[1].isNull()) {
@@ -2637,7 +2627,7 @@ static UniValue getblockfilter(const JSONRPCRequest& request)
         },
     }.Check(request);
 
-    uint256 block_hash = ParseHashV(request.params[0], "blockhash");
+    uint256 block_hash(ParseHashV(request.params[0], "blockhash"));
     std::string filtertype_name = "basic";
     if (!request.params[1].isNull()) {
         filtertype_name = request.params[1].get_str();
diff --git a/src/rpc/evo.cpp b/src/rpc/evo.cpp
index 05c70a4e79..90df3dff89 100644
--- a/src/rpc/evo.cpp
+++ b/src/rpc/evo.cpp
@@ -640,7 +640,7 @@ static UniValue protx_register_common_wrapper(const JSONRPCRequest& request,
 
         paramIdx++;
     } else {
-        uint256 collateralHash = ParseHashV(request.params[paramIdx], "collateralHash");
+        uint256 collateralHash(ParseHashV(request.params[paramIdx], "collateralHash"));
         int32_t collateralIndex = ParseInt32V(request.params[paramIdx + 1], "collateralIndex");
         if (collateralHash.IsNull() || collateralIndex < 0) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("invalid hash or index: %s-%d", collateralHash.ToString(), collateralIndex));
@@ -1405,7 +1405,7 @@ static UniValue protx_info(const JSONRPCRequest& request)
         g_txindex->BlockUntilSyncedToCurrentChain();
     }
 
-    uint256 proTxHash = ParseHashV(request.params[0], "proTxHash");
+    uint256 proTxHash(ParseHashV(request.params[0], "proTxHash"));
     auto mnList = deterministicMNManager->GetListAtChainTip();
     auto dmn = mnList.GetMN(proTxHash);
     if (!dmn) {
diff --git a/src/rpc/governance.cpp b/src/rpc/governance.cpp
index e79eb3251b..79eb21a4a3 100644
--- a/src/rpc/governance.cpp
+++ b/src/rpc/governance.cpp
@@ -213,7 +213,7 @@ static UniValue gobject_prepare(const JSONRPCRequest& request)
     COutPoint outpoint;
     outpoint.SetNull();
     if (!request.params[5].isNull() && !request.params[6].isNull()) {
-        uint256 collateralHash = ParseHashV(request.params[5], "outputHash");
+        uint256 collateralHash(ParseHashV(request.params[5], "outputHash"));
         int32_t collateralIndex = ParseInt32V(request.params[6], "outputIndex");
         if (collateralHash.IsNull() || collateralIndex < 0) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("invalid hash or index: %s-%d", collateralHash.ToString(), collateralIndex));
@@ -427,9 +427,7 @@ static UniValue gobject_vote_conf(const JSONRPCRequest& request)
 {
     gobject_vote_conf_help(request);
 
-    uint256 hash;
-
-    hash = ParseHashV(request.params[0], "Object hash");
+    uint256 hash(ParseHashV(request.params[0], "Object hash"));
     std::string strVoteSignal = request.params[1].get_str();
     std::string strVoteOutcome = request.params[2].get_str();
 
@@ -605,7 +603,7 @@ static UniValue gobject_vote_many(const JSONRPCRequest& request)
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     if (!wallet) return NullUniValue;
 
-    uint256 hash = ParseHashV(request.params[0], "Object hash");
+    uint256 hash(ParseHashV(request.params[0], "Object hash"));
     std::string strVoteSignal = request.params[1].get_str();
     std::string strVoteOutcome = request.params[2].get_str();
 
@@ -664,7 +662,7 @@ static UniValue gobject_vote_alias(const JSONRPCRequest& request)
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
     if (!wallet) return NullUniValue;
 
-    uint256 hash = ParseHashV(request.params[0], "Object hash");
+    uint256 hash(ParseHashV(request.params[0], "Object hash"));
     std::string strVoteSignal = request.params[1].get_str();
     std::string strVoteOutcome = request.params[2].get_str();
 
@@ -682,7 +680,7 @@ static UniValue gobject_vote_alias(const JSONRPCRequest& request)
 
     EnsureWalletIsUnlocked(wallet.get());
 
-    uint256 proTxHash = ParseHashV(request.params[3], "protx-hash");
+    uint256 proTxHash(ParseHashV(request.params[3], "protx-hash"));
     auto dmn = deterministicMNManager->GetListAtChainTip().GetValidMN(proTxHash);
     if (!dmn) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid or unknown proTxHash");
@@ -850,7 +848,7 @@ static UniValue gobject_get(const JSONRPCRequest& request)
     gobject_get_help(request);
 
     // COLLECT VARIABLES FROM OUR USER
-    uint256 hash = ParseHashV(request.params[0], "GovObj hash");
+    uint256 hash(ParseHashV(request.params[0], "GovObj hash"));
 
     if (g_txindex) {
         g_txindex->BlockUntilSyncedToCurrentChain();
@@ -943,11 +941,11 @@ static UniValue gobject_getcurrentvotes(const JSONRPCRequest& request)
 
     // COLLECT PARAMETERS FROM USER
 
-    uint256 hash = ParseHashV(request.params[0], "Governance hash");
+    uint256 hash(ParseHashV(request.params[0], "Governance hash"));
 
     COutPoint mnCollateralOutpoint;
     if (!request.params[1].isNull() && !request.params[2].isNull()) {
-        uint256 txid = ParseHashV(request.params[1], "Masternode Collateral hash");
+        uint256 txid(ParseHashV(request.params[1], "Masternode Collateral hash"));
         std::string strVout = request.params[2].get_str();
         mnCollateralOutpoint = COutPoint(txid, LocaleIndependentAtoi<uint32_t>(strVout));
     }
@@ -1076,11 +1074,11 @@ static UniValue voteraw(const JSONRPCRequest& request)
         RPCExamples{""}
     }.Check(request);
 
-    uint256 hashMnCollateralTx = ParseHashV(request.params[0], "mn collateral tx hash");
+    uint256 hashMnCollateralTx(ParseHashV(request.params[0], "mn collateral tx hash"));
     int nMnCollateralTxIndex = request.params[1].get_int();
     COutPoint outpoint = COutPoint(hashMnCollateralTx, nMnCollateralTxIndex);
 
-    uint256 hashGovObj = ParseHashV(request.params[2], "Governance hash");
+    uint256 hashGovObj(ParseHashV(request.params[2], "Governance hash"));
     std::string strVoteSignal = request.params[3].get_str();
     std::string strVoteOutcome = request.params[4].get_str();
 
diff --git a/src/rpc/masternode.cpp b/src/rpc/masternode.cpp
index 82af40b21c..8751753a43 100644
--- a/src/rpc/masternode.cpp
+++ b/src/rpc/masternode.cpp
@@ -420,7 +420,7 @@ static UniValue masternode_payments(const JSONRPCRequest& request)
         pindex = ::ChainActive().Tip();
     } else {
         LOCK(cs_main);
-        uint256 blockHash = ParseHashV(request.params[0], "blockhash");
+        uint256 blockHash(ParseHashV(request.params[0], "blockhash"));
         pindex = g_chainman.m_blockman.LookupBlockIndex(blockHash);
         if (pindex == nullptr) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index c65a4512c2..7d04413ac5 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -476,7 +476,7 @@ static UniValue prioritisetransaction(const JSONRPCRequest& request)
 
     LOCK(cs_main);
 
-    uint256 hash = ParseHashV(request.params[0].get_str(), "txid");
+    uint256 hash(ParseHashV(request.params[0].get_str(), "txid"));
     CAmount nAmount = request.params[1].get_int64();
 
     EnsureMemPool(request.context).PrioritiseTransaction(hash, nAmount);
@@ -726,7 +726,7 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
             // Format: <hashBestChain><nTransactionsUpdatedLast>
             std::string lpstr = lpval.get_str();
 
-            hashWatchedChain.SetHex(lpstr.substr(0, 64));
+            hashWatchedChain = ParseHashV(lpstr.substr(0, 64), "longpollid");
             nTransactionsUpdatedLastLP = LocaleIndependentAtoi<int64_t>(lpstr.substr(64));
         }
         else
diff --git a/src/rpc/quorums.cpp b/src/rpc/quorums.cpp
index 2dfeb42143..28bd9efa87 100644
--- a/src/rpc/quorums.cpp
+++ b/src/rpc/quorums.cpp
@@ -240,7 +240,7 @@ static UniValue quorum_info(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_INVALID_PARAMETER, "invalid LLMQ type");
     }
 
-    uint256 quorumHash = ParseHashV(request.params[1], "quorumHash");
+    uint256 quorumHash(ParseHashV(request.params[1], "quorumHash"));
     bool includeSkShare = false;
     if (!request.params[2].isNull()) {
         includeSkShare = ParseBoolV(request.params[2], "includeSkShare");
@@ -381,7 +381,7 @@ static UniValue quorum_memberof(const JSONRPCRequest& request)
 {
     quorum_memberof_help(request);
 
-    uint256 protxHash = ParseHashV(request.params[0], "proTxHash");
+    uint256 protxHash(ParseHashV(request.params[0], "proTxHash"));
     int scanQuorumsCount = -1;
     if (!request.params[1].isNull()) {
         scanQuorumsCount = ParseInt32V(request.params[1], "scanQuorumsCount");
@@ -530,8 +530,8 @@ static UniValue quorum_sigs_cmd(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_INVALID_PARAMETER, "invalid LLMQ type");
     }
 
-    uint256 id = ParseHashV(request.params[1], "id");
-    uint256 msgHash = ParseHashV(request.params[2], "msgHash");
+    uint256 id(ParseHashV(request.params[1], "id"));
+    uint256 msgHash(ParseHashV(request.params[2], "msgHash"));
 
     if (cmd == "quorumsign") {
         uint256 quorumHash;
@@ -590,7 +590,7 @@ static UniValue quorum_sigs_cmd(const JSONRPCRequest& request)
             return llmq_ctx.sigman->VerifyRecoveredSig(llmqType, *llmq_ctx.qman, signHeight, id, msgHash, sig, 0) ||
                    llmq_ctx.sigman->VerifyRecoveredSig(llmqType, *llmq_ctx.qman, signHeight, id, msgHash, sig, signOffset);
         } else {
-            uint256 quorumHash = ParseHashV(request.params[4], "quorumHash");
+            uint256 quorumHash(ParseHashV(request.params[4], "quorumHash"));
             llmq::CQuorumCPtr quorum = llmq_ctx.qman->GetQuorum(llmqType, quorumHash);
 
             if (!quorum) {
@@ -642,7 +642,7 @@ static UniValue quorum_selectquorum(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_INVALID_PARAMETER, "invalid LLMQ type");
     }
 
-    uint256 id = ParseHashV(request.params[1], "id");
+    uint256 id(ParseHashV(request.params[1], "id"));
 
     UniValue ret(UniValue::VOBJ);
 
@@ -723,7 +723,7 @@ static UniValue quorum_getdata(const JSONRPCRequest& request)
 
     NodeId nodeId = ParseInt64V(request.params[0], "nodeId");
     Consensus::LLMQType llmqType = static_cast<Consensus::LLMQType>(ParseInt32V(request.params[1], "llmqType"));
-    uint256 quorumHash = ParseHashV(request.params[2], "quorumHash");
+    uint256 quorumHash(ParseHashV(request.params[2], "quorumHash"));
     uint16_t nDataMask = static_cast<uint16_t>(ParseInt32V(request.params[3], "dataMask"));
     uint256 proTxHash;
 
@@ -871,7 +871,7 @@ static UniValue verifychainlock(const JSONRPCRequest& request)
 {
     verifychainlock_help(request);
 
-    const uint256 nBlockHash = ParseHashV(request.params[0], "blockHash");
+    const uint256 nBlockHash(ParseHashV(request.params[0], "blockHash"));
 
     CBLSSignature chainLockSig;
     if (!chainLockSig.SetHexStr(request.params[1].get_str())) {
@@ -915,8 +915,8 @@ static UniValue verifyislock(const JSONRPCRequest& request)
 {
     verifyislock_help(request);
 
-    uint256 id = ParseHashV(request.params[0], "id");
-    uint256 txid = ParseHashV(request.params[1], "txid");
+    uint256 id(ParseHashV(request.params[0], "id"));
+    uint256 txid(ParseHashV(request.params[1], "txid"));
 
     CBLSSignature sig;
     if (!sig.SetHexStr(request.params[2].get_str())) {
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 22e6002c87..cd1891138c 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -297,10 +297,7 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
     UniValue txids = request.params[0].get_array();
     for (unsigned int idx = 0; idx < txids.size(); idx++) {
         const UniValue& txid = txids[idx];
-        if (txid.get_str().length() != 64 || !IsHex(txid.get_str())) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid txid ")+txid.get_str());
-        }
-        uint256 hash(uint256S(txid.get_str()));
+        uint256 hash(ParseHashV(txid, "txid"));
         if (setTxids.count(hash)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated txid: ")+txid.get_str());
         }
@@ -312,7 +309,7 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
     uint256 hashBlock;
     if (!request.params[1].isNull()) {
         LOCK(cs_main);
-        hashBlock = uint256S(request.params[1].get_str());
+        hashBlock = ParseHashV(request.params[1], "blockhash");
         pblockindex = g_chainman.m_blockman.LookupBlockIndex(hashBlock);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index 3c21a8c6ae..6b8b48a26a 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -88,16 +88,12 @@ CAmount AmountFromValue(const UniValue& value)
 
 uint256 ParseHashV(const UniValue& v, std::string strName)
 {
-    std::string strHex;
-    if (v.isStr())
-        strHex = v.get_str();
+    std::string strHex{v.get_str()};
+    if (64 != strHex.length())
+        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("%s must be of length %d (not %d, for '%s')", strName, 64, strHex.length(), strHex));
     if (!IsHex(strHex)) // Note: IsHex("") is false
         throw JSONRPCError(RPC_INVALID_PARAMETER, strName+" must be hexadecimal string (not '"+strHex+"')");
-    if (64 != strHex.length())
-        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("%s must be of length %d (not %d)", strName, 64, strHex.length()));
-    uint256 result;
-    result.SetHex(strHex);
-    return result;
+    return uint256S(strHex);
 }
 uint256 ParseHashO(const UniValue& o, std::string strKey)
 {
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 3be31a41ad..8926e9135b 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -358,8 +358,7 @@ UniValue removeprunedfunds(const JSONRPCRequest& request)
 
     LOCK(pwallet->cs_wallet);
 
-    uint256 hash;
-    hash.SetHex(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "txid"));
     std::vector<uint256> vHash;
     vHash.push_back(hash);
     std::vector<uint256> vHashOut;
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index b174178ae4..b9171d10f0 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1582,7 +1582,7 @@ static UniValue listsinceblock(const JSONRPCRequest& request)
 
     uint256 blockId;
     if (!request.params[0].isNull() && !request.params[0].get_str().empty()) {
-        blockId.SetHex(request.params[0].get_str());
+        blockId = ParseHashV(request.params[0], "blockhash");
         height = pwallet->chain().findFork(blockId, &altheight);
 
         if (!height) {
@@ -1707,8 +1707,7 @@ static UniValue gettransaction(const JSONRPCRequest& request)
 
     LOCK(pwallet->cs_wallet);
 
-    uint256 hash;
-    hash.SetHex(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "txid"));
 
     isminefilter filter = ISMINE_SPENDABLE;
 
@@ -1772,8 +1771,7 @@ static UniValue abandontransaction(const JSONRPCRequest& request)
 
     LOCK(pwallet->cs_wallet);
 
-    uint256 hash;
-    hash.SetHex(request.params[0].get_str());
+    uint256 hash(ParseHashV(request.params[0], "txid"));
 
     if (!pwallet->mapWallet.count(hash)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid or non-wallet transaction id");
@@ -2176,17 +2174,13 @@ static UniValue lockunspent(const JSONRPCRequest& request)
                 {"vout", UniValueType(UniValue::VNUM)},
             });
 
-        const std::string& txid = find_value(o, "txid").get_str();
-        if (!IsHex(txid)) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, expected hex txid");
-        }
-
+        const uint256 txid(ParseHashO(o, "txid"));
         const int nOutput = find_value(o, "vout").get_int();
         if (nOutput < 0) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout cannot be negative");
         }
 
-        const COutPoint outpt(uint256S(txid), nOutput);
+        const COutPoint outpt(txid, nOutput);
 
         const auto it = pwallet->mapWallet.find(outpt.hash);
         if (it == pwallet->mapWallet.end()) {
diff --git a/test/functional/mining_prioritisetransaction.py b/test/functional/mining_prioritisetransaction.py
index 98f7922e54..9af7acdc20 100755
--- a/test/functional/mining_prioritisetransaction.py
+++ b/test/functional/mining_prioritisetransaction.py
@@ -30,7 +30,7 @@ class PrioritiseTransactionTest(BitcoinTestFramework):
         assert_raises_rpc_error(-1, "prioritisetransaction", self.nodes[0].prioritisetransaction, '', 0, 0)
 
         # Test `prioritisetransaction` invalid `txid`
-        assert_raises_rpc_error(-8, "txid must be hexadecimal string", self.nodes[0].prioritisetransaction, txid='foo', fee_delta=0)
+        assert_raises_rpc_error(-8, "txid must be of length 64 (not 3, for 'foo')", self.nodes[0].prioritisetransaction, txid='foo', fee_delta=0)
         assert_raises_rpc_error(-8, "txid must be hexadecimal string (not 'Zd1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000')", self.nodes[0].prioritisetransaction, txid='Zd1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000', fee_delta=0)
 
         txid = '1d1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000'
diff --git a/test/functional/p2p_compactblocks.py b/test/functional/p2p_compactblocks.py
index 85ce4e138b..cf4cb9135a 100755
--- a/test/functional/p2p_compactblocks.py
+++ b/test/functional/p2p_compactblocks.py
@@ -279,7 +279,7 @@ class CompactBlocksTest(BitcoinTestFramework):
         block_hash = int(node.generate(1)[0], 16)
 
         # Store the raw block in our internal format.
-        block = FromHex(CBlock(), node.getblock("%02x" % block_hash, False))
+        block = FromHex(CBlock(), node.getblock("%064x" % block_hash, False))
         for tx in block.vtx:
             tx.calc_sha256()
         block.rehash()
diff --git a/test/functional/p2p_sendheaders.py b/test/functional/p2p_sendheaders.py
index dc42f638aa..c9f709580a 100755
--- a/test/functional/p2p_sendheaders.py
+++ b/test/functional/p2p_sendheaders.py
@@ -394,7 +394,7 @@ class SendHeadersTest(BitcoinTestFramework):
 
             block_time += 9
 
-            fork_point = self.nodes[0].getblock("%02x" % new_block_hashes[0])["previousblockhash"]
+            fork_point = self.nodes[0].getblock("%064x" % new_block_hashes[0])["previousblockhash"]
             fork_point = int(fork_point, 16)
 
             # Use getblocks/getdata
diff --git a/test/functional/rpc_blockchain.py b/test/functional/rpc_blockchain.py
index d20670c51d..0220069cb3 100755
--- a/test/functional/rpc_blockchain.py
+++ b/test/functional/rpc_blockchain.py
@@ -142,7 +142,9 @@ class BlockchainTest(BitcoinTestFramework):
 
         # Test `getchaintxstats` invalid `blockhash`
         assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].getchaintxstats, blockhash=0)
-        assert_raises_rpc_error(-5, "Block not found", self.nodes[0].getchaintxstats, blockhash='0')
+        assert_raises_rpc_error(-8, "blockhash must be of length 64 (not 1, for '0')", self.nodes[0].getchaintxstats, blockhash='0')
+        assert_raises_rpc_error(-8, "blockhash must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[0].getchaintxstats, blockhash='ZZZ0000000000000000000000000000000000000000000000000000000000000')
+        assert_raises_rpc_error(-5, "Block not found", self.nodes[0].getchaintxstats, blockhash='0000000000000000000000000000000000000000000000000000000000000000')
         blockhash = self.nodes[0].getblockhash(200)
         self.nodes[0].invalidateblock(blockhash)
         assert_raises_rpc_error(-8, "Block is not in main chain", self.nodes[0].getchaintxstats, blockhash=blockhash)
@@ -244,7 +246,9 @@ class BlockchainTest(BitcoinTestFramework):
     def _test_getblockheader(self):
         node = self.nodes[0]
 
-        assert_raises_rpc_error(-5, "Block not found", node.getblockheader, "nonsense")
+        assert_raises_rpc_error(-8, "hash must be of length 64 (not 8, for 'nonsense')", node.getblockheader, "nonsense")
+        assert_raises_rpc_error(-8, "hash must be hexadecimal string (not 'ZZZ7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844')", node.getblockheader, "ZZZ7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844")
+        assert_raises_rpc_error(-5, "Block not found", node.getblockheader, "0cf7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844")
 
         besthash = node.getbestblockhash()
         secondbesthash = node.getblockhash(199)
diff --git a/test/functional/rpc_rawtransaction.py b/test/functional/rpc_rawtransaction.py
index 46b9461fb4..35c0d94ae7 100755
--- a/test/functional/rpc_rawtransaction.py
+++ b/test/functional/rpc_rawtransaction.py
@@ -90,8 +90,9 @@ class RawTransactionsTest(BitcoinTestFramework):
         txid = '1d1d4e24ed99057e84c3f80fd8fbec79ed9e1acee37da269356ecea000000000'
         assert_raises_rpc_error(-3, "Expected type array", self.nodes[0].createrawtransaction, 'foo', {})
         assert_raises_rpc_error(-1, "JSON value is not an object as expected", self.nodes[0].createrawtransaction, ['foo'], {})
-        assert_raises_rpc_error(-8, "txid must be hexadecimal string", self.nodes[0].createrawtransaction, [{}], {})
-        assert_raises_rpc_error(-8, "txid must be hexadecimal string", self.nodes[0].createrawtransaction, [{'txid': 'foo'}], {})
+        assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].createrawtransaction, [{}], {})
+        assert_raises_rpc_error(-8, "txid must be of length 64 (not 3, for 'foo')", self.nodes[0].createrawtransaction, [{'txid': 'foo'}], {})
+        assert_raises_rpc_error(-8, "txid must be hexadecimal string (not 'ZZZ7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844')", self.nodes[0].createrawtransaction, [{'txid': 'ZZZ7bb8b1697ea987f3b223ba7819250cae33efacb068d23dc24859824a77844'}], {})
         assert_raises_rpc_error(-8, "Invalid parameter, missing vout key", self.nodes[0].createrawtransaction, [{'txid': txid}], {})
         assert_raises_rpc_error(-8, "Invalid parameter, missing vout key", self.nodes[0].createrawtransaction, [{'txid': txid, 'vout': 'foo'}], {})
         assert_raises_rpc_error(-8, "Invalid parameter, vout cannot be negative", self.nodes[0].createrawtransaction, [{'txid': txid, 'vout': -1}], {})
@@ -171,9 +172,10 @@ class RawTransactionsTest(BitcoinTestFramework):
         # We should not get the tx if we provide an unrelated block
         assert_raises_rpc_error(-5, "No such transaction found", self.nodes[0].getrawtransaction, tx, True, block2)
         # An invalid block hash should raise the correct errors
-        assert_raises_rpc_error(-8, "parameter 3 must be hexadecimal", self.nodes[0].getrawtransaction, tx, True, True)
-        assert_raises_rpc_error(-8, "parameter 3 must be hexadecimal", self.nodes[0].getrawtransaction, tx, True, "foobar")
-        assert_raises_rpc_error(-8, "parameter 3 must be of length 64", self.nodes[0].getrawtransaction, tx, True, "abcd1234")
+        assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].getrawtransaction, tx, True, True)
+        assert_raises_rpc_error(-8, "parameter 3 must be of length 64 (not 6, for 'foobar')", self.nodes[0].getrawtransaction, tx, True, "foobar")
+        assert_raises_rpc_error(-8, "parameter 3 must be of length 64 (not 8, for 'abcd1234')", self.nodes[0].getrawtransaction, tx, True, "abcd1234")
+        assert_raises_rpc_error(-8, "parameter 3 must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[0].getrawtransaction, tx, True, "ZZZ0000000000000000000000000000000000000000000000000000000000000")
         assert_raises_rpc_error(-5, "Block hash not found", self.nodes[0].getrawtransaction, tx, True, "0000000000000000000000000000000000000000000000000000000000000000")
         # Undo the blocks and check in_active_chain
         self.nodes[0].invalidateblock(block1)
diff --git a/test/functional/rpc_txoutproof.py b/test/functional/rpc_txoutproof.py
index b75966b85c..65d5b5eda8 100755
--- a/test/functional/rpc_txoutproof.py
+++ b/test/functional/rpc_txoutproof.py
@@ -69,13 +69,19 @@ class MerkleBlockTest(BitcoinTestFramework):
         txid_spent = txin_spent["txid"]
         txid_unspent = txid1 if txin_spent["txid"] != txid1 else txid2
 
+        # Invalid txids
+        assert_raises_rpc_error(-8, "txid must be of length 64 (not 32, for '00000000000000000000000000000000')", self.nodes[2].gettxoutproof, ["00000000000000000000000000000000"], blockhash)
+        assert_raises_rpc_error(-8, "txid must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[2].gettxoutproof, ["ZZZ0000000000000000000000000000000000000000000000000000000000000"], blockhash)
+        # Invalid blockhashes
+        assert_raises_rpc_error(-8, "blockhash must be of length 64 (not 32, for '00000000000000000000000000000000')", self.nodes[2].gettxoutproof, [txid_spent], "00000000000000000000000000000000")
+        assert_raises_rpc_error(-8, "blockhash must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')", self.nodes[2].gettxoutproof, [txid_spent], "ZZZ0000000000000000000000000000000000000000000000000000000000000")
         # We can't find the block from a fully-spent tx
         # Doesn't apply to Dash Core - we have txindex always on
         # assert_raises_rpc_error(-5, "Transaction not yet in block", self.nodes[2].gettxoutproof, [txid_spent])
         # We can get the proof if we specify the block
         assert_equal(self.nodes[2].verifytxoutproof(self.nodes[2].gettxoutproof([txid_spent], blockhash)), [txid_spent])
         # We can't get the proof if we specify a non-existent block
-        assert_raises_rpc_error(-5, "Block not found", self.nodes[2].gettxoutproof, [txid_spent], "00000000000000000000000000000000")
+        assert_raises_rpc_error(-5, "Block not found", self.nodes[2].gettxoutproof, [txid_spent], "0000000000000000000000000000000000000000000000000000000000000000")
         # We can get the proof if the transaction is unspent
         assert_equal(self.nodes[2].verifytxoutproof(self.nodes[2].gettxoutproof([txid_unspent])), [txid_unspent])
         # We can get the proof if we provide a list of transactions and one of them is unspent. The ordering of the list should not matter.
diff --git a/test/functional/wallet_basic.py b/test/functional/wallet_basic.py
index d43bb1312d..d419bfb946 100755
--- a/test/functional/wallet_basic.py
+++ b/test/functional/wallet_basic.py
@@ -121,9 +121,15 @@ class WalletTest(BitcoinTestFramework):
         assert_equal([unspent_0], self.nodes[2].listlockunspent())
         self.nodes[2].lockunspent(True, [unspent_0])
         assert_equal(len(self.nodes[2].listlockunspent()), 0)
-        assert_raises_rpc_error(-8, "Invalid parameter, unknown transaction",
+        assert_raises_rpc_error(-8, "txid must be of length 64 (not 34, for '0000000000000000000000000000000000')",
                                 self.nodes[2].lockunspent, False,
                                 [{"txid": "0000000000000000000000000000000000", "vout": 0}])
+        assert_raises_rpc_error(-8, "txid must be hexadecimal string (not 'ZZZ0000000000000000000000000000000000000000000000000000000000000')",
+                                self.nodes[2].lockunspent, False,
+                                [{"txid": "ZZZ0000000000000000000000000000000000000000000000000000000000000", "vout": 0}])
+        assert_raises_rpc_error(-8, "Invalid parameter, unknown transaction",
+                                self.nodes[2].lockunspent, False,
+                                [{"txid": "0000000000000000000000000000000000000000000000000000000000000000", "vout": 0}])
         assert_raises_rpc_error(-8, "Invalid parameter, vout index out of bounds",
                                 self.nodes[2].lockunspent, False,
                                 [{"txid": unspent_0["txid"], "vout": 999}])
diff --git a/test/functional/wallet_listsinceblock.py b/test/functional/wallet_listsinceblock.py
index 3aa85bad68..7715d5f5f7 100755
--- a/test/functional/wallet_listsinceblock.py
+++ b/test/functional/wallet_listsinceblock.py
@@ -66,8 +66,10 @@ class ListSinceBlockTest(BitcoinTestFramework):
                                 "42759cde25462784395a337460bde75f58e73d3f08bd31fdc3507cbac856a2c4")
         assert_raises_rpc_error(-5, "Block not found", self.nodes[0].listsinceblock,
                                 "0000000000000000000000000000000000000000000000000000000000000000")
-        assert_raises_rpc_error(-5, "Block not found", self.nodes[0].listsinceblock,
+        assert_raises_rpc_error(-8, "blockhash must be of length 64 (not 11, for 'invalid-hex')", self.nodes[0].listsinceblock,
                                 "invalid-hex")
+        assert_raises_rpc_error(-8, "blockhash must be hexadecimal string (not 'Z000000000000000000000000000000000000000000000000000000000000000')", self.nodes[0].listsinceblock,
+                                "Z000000000000000000000000000000000000000000000000000000000000000")
 
     def test_reorg(self):
         '''