diff --git a/configure.ac b/configure.ac
index 6b4cba8fe284..77c8c946487f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -404,6 +404,7 @@ if test "x$enable_werror" = "xyes"; then
   AX_CHECK_COMPILE_FLAG([-Werror=date-time],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=date-time"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Werror=return-type],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=return-type"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Werror=conditional-uninitialized],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=conditional-uninitialized"],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_COMPILE_FLAG([-Werror=sign-compare],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=sign-compare"],,[[$CXXFLAG_WERROR]])
   dnl -Wsuggest-override is broken with GCC before 9.2
   dnl https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78010
   AX_CHECK_COMPILE_FLAG([-Werror=suggest-override],[ERROR_CXXFLAGS="$ERROR_CXXFLAGS -Werror=suggest-override"],,[[$CXXFLAG_WERROR]],
@@ -423,6 +424,7 @@ if test "x$CXXFLAGS_overridden" = "xno"; then
   AX_CHECK_COMPILE_FLAG([-Wunused-variable],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wunused-variable"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wdate-time],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wdate-time"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wconditional-uninitialized],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wconditional-uninitialized"],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_COMPILE_FLAG([-Wsign-compare],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wsign-compare"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wsuggest-override],[WARN_CXXFLAGS="$WARN_CXXFLAGS -Wsuggest-override"],,[[$CXXFLAG_WERROR]],
                         [AC_LANG_SOURCE([[struct A { virtual void f(); }; struct B : A { void f() final; };]])])
 
diff --git a/depends/packages/bls-dash.mk b/depends/packages/bls-dash.mk
index 74f45b8f61fd..17e2f3459704 100644
--- a/depends/packages/bls-dash.mk
+++ b/depends/packages/bls-dash.mk
@@ -1,10 +1,10 @@
 package=bls-dash
-$(package)_version=1.1.0
+$(package)_version=1.2.0
 $(package)_download_path=https://github.com/dashpay/bls-signatures/archive
 $(package)_download_file=$($(package)_version).tar.gz
 $(package)_file_name=$(package)-$($(package)_download_file)
 $(package)_build_subdir=build
-$(package)_sha256_hash=276c8573104e5f18bb5b9fd3ffd49585dda5ba5f6de2de74759dda8ca5a9deac
+$(package)_sha256_hash=94e49f3eaa29bc1f354cd569c00f4f4314d1c8ab4758527c248b67da9686135a
 $(package)_dependencies=gmp cmake
 $(package)_patches=gcc_alignment_cast.patch
 $(package)_darwin_triplet=x86_64-apple-darwin19
diff --git a/src/bls/bls_worker.cpp b/src/bls/bls_worker.cpp
index 0bf5a6a34d93..c6a4745fe7d2 100644
--- a/src/bls/bls_worker.cpp
+++ b/src/bls/bls_worker.cpp
@@ -73,13 +73,13 @@ void CBLSWorker::Stop()
     workerPool.stop(true);
 }
 
-bool CBLSWorker::GenerateContributions(int quorumThreshold, const BLSIdVector& ids, BLSVerificationVectorPtr& vvecRet, BLSSecretKeyVector& skSharesRet)
+bool CBLSWorker::GenerateContributions(uint32_t quorumThreshold, const BLSIdVector& ids, BLSVerificationVectorPtr& vvecRet, BLSSecretKeyVector& skSharesRet)
 {
     auto svec = BLSSecretKeyVector((size_t)quorumThreshold);
     vvecRet = std::make_shared<BLSVerificationVector>((size_t)quorumThreshold);
     skSharesRet.resize(ids.size());
 
-    for (int i = 0; i < quorumThreshold; i++) {
+    for (uint32_t i = 0; i < quorumThreshold; i++) {
         svec[i].MakeNewKey();
     }
     size_t batchSize = 8;
diff --git a/src/bls/bls_worker.h b/src/bls/bls_worker.h
index 25f137732b6e..f16670057a11 100644
--- a/src/bls/bls_worker.h
+++ b/src/bls/bls_worker.h
@@ -55,7 +55,7 @@ class CBLSWorker
     void Start();
     void Stop();
 
-    bool GenerateContributions(int threshold, const BLSIdVector& ids, BLSVerificationVectorPtr& vvecRet, BLSSecretKeyVector& skSharesRet);
+    bool GenerateContributions(uint32_t threshold, const BLSIdVector& ids, BLSVerificationVectorPtr& vvecRet, BLSSecretKeyVector& skSharesRet);
 
     // The following functions are all used to aggregate verification (public key) vectors
     // Inputs are in the following form:
diff --git a/src/coinjoin/client.cpp b/src/coinjoin/client.cpp
index 53fcda8b5264..ca99ed4d8092 100644
--- a/src/coinjoin/client.cpp
+++ b/src/coinjoin/client.cpp
@@ -1010,8 +1010,8 @@ CDeterministicMNCPtr CCoinJoinClientManager::GetRandomNotUsedMasternode()
 {
     auto mnList = deterministicMNManager->GetListAtChainTip();
 
-    size_t nCountEnabled = mnList.GetValidMNsCount();
-    size_t nCountNotExcluded = nCountEnabled - vecMasternodesUsed.size();
+    int nCountEnabled = mnList.GetValidMNsCount();
+    int nCountNotExcluded = nCountEnabled - vecMasternodesUsed.size();
 
     LogPrint(BCLog::COINJOIN, "CCoinJoinClientManager::%s -- %d enabled masternodes, %d masternodes to choose from\n", __func__, nCountEnabled, nCountNotExcluded);
     if (nCountNotExcluded < 1) {
@@ -1340,7 +1340,7 @@ bool CCoinJoinClientSession::PrepareDenominate(int nMinRounds, int nMaxRounds, s
 
     // NOTE: No need to randomize order of inputs because they were
     // initially shuffled in CWallet::SelectTxDSInsByDenomination already.
-    int nSteps{0};
+    uint64_t nSteps{0};
     vecPSInOutPairsRet.clear();
 
     // Try to add up to COINJOIN_ENTRY_MAX_SIZE of every needed denomination
diff --git a/src/coinjoin/coinjoin.cpp b/src/coinjoin/coinjoin.cpp
index de7bac827b22..bd56178654a6 100644
--- a/src/coinjoin/coinjoin.cpp
+++ b/src/coinjoin/coinjoin.cpp
@@ -128,7 +128,7 @@ bool CCoinJoinBroadcastTx::IsValidStructure() const
     if (tx->vin.size() != tx->vout.size()) {
         return false;
     }
-    if (tx->vin.size() < CCoinJoin::GetMinPoolParticipants()) {
+    if (tx->vin.size() < static_cast<size_t>(CCoinJoin::GetMinPoolParticipants())) {
         return false;
     }
     if (tx->vin.size() > CCoinJoin::GetMaxPoolParticipants() * COINJOIN_ENTRY_MAX_SIZE) {
diff --git a/src/coinjoin/coinjoin.h b/src/coinjoin/coinjoin.h
index 1f9bb07a27b0..d012c22db6ff 100644
--- a/src/coinjoin/coinjoin.h
+++ b/src/coinjoin/coinjoin.h
@@ -369,7 +369,7 @@ class CCoinJoinBaseSession
     int GetState() const { return nState; }
     std::string GetStateString() const;
 
-    int GetEntriesCount() const { LOCK(cs_coinjoin); return vecEntries.size(); }
+    size_t GetEntriesCount() const { LOCK(cs_coinjoin); return vecEntries.size(); }
 };
 
 // base class
diff --git a/src/coinjoin/server.cpp b/src/coinjoin/server.cpp
index 419a0487649d..f687abbca245 100644
--- a/src/coinjoin/server.cpp
+++ b/src/coinjoin/server.cpp
@@ -282,7 +282,7 @@ void CCoinJoinServer::CheckPool(CConnman& connman)
     // Check for Time Out
     // If we timed out while accepting entries, then if we have more than minimum, create final tx
     if (nState == POOL_STATE_ACCEPTING_ENTRIES && CCoinJoinServer::HasTimedOut()
-            && GetEntriesCount() >= CCoinJoin::GetMinPoolParticipants()) {
+            && GetEntriesCount() >= static_cast<size_t>(CCoinJoin::GetMinPoolParticipants())) {
         // Punish misbehaving participants
         ChargeFees(connman);
         // Try to complete this session ignoring the misbehaving ones
@@ -307,7 +307,7 @@ void CCoinJoinServer::CreateFinalTransaction(CConnman& connman)
     CMutableTransaction txNew;
 
     // make our new transaction
-    for (int i = 0; i < GetEntriesCount(); i++) {
+    for (size_t i = 0; i < GetEntriesCount(); i++) {
         for (const auto& txout : vecEntries[i].vecTxOut) {
             txNew.vout.push_back(txout);
         }
@@ -432,10 +432,10 @@ void CCoinJoinServer::ChargeFees(CConnman& connman) const
     if (vecOffendersCollaterals.empty()) return;
 
     //mostly offending? Charge sometimes
-    if ((int)vecOffendersCollaterals.size() >= vecSessionCollaterals.size() - 1 && GetRandInt(100) > 33) return;
+    if (vecOffendersCollaterals.size() >= vecSessionCollaterals.size() - 1 && GetRandInt(100) > 33) return;
 
     //everyone is an offender? That's not right
-    if ((int)vecOffendersCollaterals.size() >= vecSessionCollaterals.size()) return;
+    if (vecOffendersCollaterals.size() >= vecSessionCollaterals.size()) return;
 
     //charge one of the offenders randomly
     Shuffle(vecOffendersCollaterals.begin(), vecOffendersCollaterals.end(), FastRandomContext());
@@ -667,7 +667,7 @@ bool CCoinJoinServer::AddScriptSig(const CTxIn& txinNew)
             LogPrint(BCLog::COINJOIN, "CCoinJoinServer::AddScriptSig -- adding to finalMutableTransaction, scriptSig=%s\n", ScriptToAsmStr(txinNew.scriptSig).substr(0, 24));
         }
     }
-    for (int i = 0; i < GetEntriesCount(); i++) {
+    for (size_t i = 0; i < GetEntriesCount(); i++) {
         if (vecEntries[i].AddScriptSig(txinNew)) {
             LogPrint(BCLog::COINJOIN, "CCoinJoinServer::AddScriptSig -- adding to entries, scriptSig=%s\n", ScriptToAsmStr(txinNew.scriptSig).substr(0, 24));
             return true;
diff --git a/src/evo/cbtx.cpp b/src/evo/cbtx.cpp
index e001f4d2b53e..6030659069dc 100644
--- a/src/evo/cbtx.cpp
+++ b/src/evo/cbtx.cpp
@@ -215,7 +215,7 @@ bool CalcCbTxMerkleRootQuorums(const CBlock& block, const CBlockIndex* pindexPre
             auto qcHash = ::SerializeHash(qc.commitment);
             const auto& llmq_params = llmq::GetLLMQParams(qc.commitment.llmqType);
             auto& v = qcHashes[llmq_params.type];
-            if (v.size() == llmq_params.signingActiveQuorumCount) {
+            if (v.size() == static_cast<size_t>(llmq_params.signingActiveQuorumCount)) {
                 // we pop the last entry, which is actually the oldest quorum as GetMinedAndActiveCommitmentsUntilBlock
                 // returned quorums in reversed order. This pop and later push can only work ONCE, but we rely on the
                 // fact that a block can only contain a single commitment for one LLMQ type
@@ -223,7 +223,7 @@ bool CalcCbTxMerkleRootQuorums(const CBlock& block, const CBlockIndex* pindexPre
             }
             v.emplace_back(qcHash);
             hashCount++;
-            if (v.size() > llmq_params.signingActiveQuorumCount) {
+            if (v.size() > static_cast<size_t>(llmq_params.signingActiveQuorumCount)) {
                 return state.DoS(100, false, REJECT_INVALID, "excess-quorums-calc-cbtx-quorummerkleroot");
             }
         }
diff --git a/src/evo/deterministicmns.h b/src/evo/deterministicmns.h
index 120f82b4d134..3af7ff352841 100644
--- a/src/evo/deterministicmns.h
+++ b/src/evo/deterministicmns.h
@@ -370,9 +370,9 @@ class CDeterministicMNList
         return mnMap.size();
     }
 
-    size_t GetValidMNsCount() const
+    int GetValidMNsCount() const
     {
-        size_t count = 0;
+        int count = 0;
         for (const auto& p : mnMap) {
             if (IsMNValid(p.second)) {
                 count++;
diff --git a/src/governance/governance.cpp b/src/governance/governance.cpp
index d1fd99d98aa6..8cf8691ba2e7 100644
--- a/src/governance/governance.cpp
+++ b/src/governance/governance.cpp
@@ -970,7 +970,7 @@ int CGovernanceManager::RequestGovernanceObjectVotes(const std::vector<CNode*>&
     int nMaxObjRequestsPerNode = 1;
     size_t nProjectedVotes = 2000;
     if (Params().NetworkIDString() != CBaseChainParams::MAIN) {
-        nMaxObjRequestsPerNode = std::max(1, int(nProjectedVotes / std::max(1, (int)deterministicMNManager->GetListAtChainTip().GetValidMNsCount())));
+        nMaxObjRequestsPerNode = std::max(1, int(nProjectedVotes / std::max(1, deterministicMNManager->GetListAtChainTip().GetValidMNsCount())));
     }
 
     {
diff --git a/src/governance/object.cpp b/src/governance/object.cpp
index e904ae276f67..cb8f4976460b 100644
--- a/src/governance/object.cpp
+++ b/src/governance/object.cpp
@@ -682,7 +682,7 @@ void CGovernanceObject::UpdateSentinelVariables()
 {
     // CALCULATE MINIMUM SUPPORT LEVELS REQUIRED
 
-    int nMnCount = (int)deterministicMNManager->GetListAtChainTip().GetValidMNsCount();
+    int nMnCount = deterministicMNManager->GetListAtChainTip().GetValidMNsCount();
     if (nMnCount == 0) return;
 
     // CALCULATE THE MINIMUM VOTE COUNT REQUIRED FOR FULL SIGNAL
diff --git a/src/llmq/blockprocessor.cpp b/src/llmq/blockprocessor.cpp
index c1831cec5568..8fc154dbb0d7 100644
--- a/src/llmq/blockprocessor.cpp
+++ b/src/llmq/blockprocessor.cpp
@@ -460,7 +460,7 @@ std::vector<const CBlockIndex*> CQuorumBlockProcessor::GetMinedCommitmentsUntilB
         }
 
         uint32_t nMinedHeight = std::numeric_limits<uint32_t>::max() - be32toh(std::get<2>(curKey));
-        if (nMinedHeight > pindex->nHeight) {
+        if (nMinedHeight > static_cast<uint32_t>(pindex->nHeight)) {
             break;
         }
 
diff --git a/src/llmq/commitment.cpp b/src/llmq/commitment.cpp
index 99fb87265132..adc904bfa806 100644
--- a/src/llmq/commitment.cpp
+++ b/src/llmq/commitment.cpp
@@ -69,7 +69,7 @@ bool CFinalCommitment::Verify(const CBlockIndex* pQuorumBaseBlockIndex, bool che
     }
 
     auto members = CLLMQUtils::GetAllQuorumMembers(llmq_params, pQuorumBaseBlockIndex);
-    for (size_t i = members.size(); i < llmq_params.size; i++) {
+    for (size_t i = members.size(); i < static_cast<size_t>(llmq_params.size); i++) {
         if (validMembers[i]) {
             LogPrintfFinalCommitment("invalid validMembers bitset. bit %d should not be set\n", i);
             return false;
@@ -122,11 +122,11 @@ bool CFinalCommitment::VerifyNull() const
 
 bool CFinalCommitment::VerifySizes(const Consensus::LLMQParams& params) const
 {
-    if (signers.size() != params.size) {
+    if (signers.size() != static_cast<size_t>(params.size)) {
         LogPrintfFinalCommitment("invalid signers.size=%d\n", signers.size());
         return false;
     }
-    if (validMembers.size() != params.size) {
+    if (validMembers.size() != static_cast<size_t>(params.size)) {
         LogPrintfFinalCommitment("invalid signers.size=%d\n", signers.size());
         return false;
     }
@@ -144,7 +144,7 @@ bool CheckLLMQCommitment(const CTransaction& tx, const CBlockIndex* pindexPrev,
         return state.DoS(100, false, REJECT_INVALID, "bad-qc-version");
     }
 
-    if (qcTx.nHeight != pindexPrev->nHeight + 1) {
+    if (qcTx.nHeight != static_cast<uint32_t>(pindexPrev->nHeight + 1)) {
         return state.DoS(100, false, REJECT_INVALID, "bad-qc-height");
     }
 
diff --git a/src/llmq/dkgsession.cpp b/src/llmq/dkgsession.cpp
index 4b64fee7d7c1..a01aacb19753 100644
--- a/src/llmq/dkgsession.cpp
+++ b/src/llmq/dkgsession.cpp
@@ -120,7 +120,7 @@ bool CDKGSession::Init(const CBlockIndex* _pQuorumBaseBlockIndex, const std::vec
 
     CDKGLogger logger(*this, __func__);
 
-    if (mns.size() < params.minSize) {
+    if (mns.size() < static_cast<size_t>(params.minSize)) {
         logger.Batch("not enough members (%d < %d), aborting init", mns.size(), params.minSize);
         return false;
     }
@@ -235,7 +235,7 @@ bool CDKGSession::PreVerifyMessage(const CDKGContribution& qc, bool& retBan) con
         retBan = true;
         return false;
     }
-    if (qc.vvec->size() != params.threshold) {
+    if (qc.vvec->size() != static_cast<size_t>(params.threshold)) {
         logger.Batch("invalid verification vector length");
         retBan = true;
         return false;
@@ -655,7 +655,7 @@ void CDKGSession::VerifyAndJustify(CDKGPendingMessages& pendingMessages)
         if (m->bad) {
             continue;
         }
-        if (m->badMemberVotes.size() >= params.dkgBadVotesThreshold) {
+        if (m->badMemberVotes.size() >= static_cast<size_t>(params.dkgBadVotesThreshold)) {
             logger.Batch("%s marked as bad as %d other members voted for this", m->dmn->proTxHash.ToString(), m->badMemberVotes.size());
             MarkBadMember(m->idx);
             continue;
@@ -1082,7 +1082,7 @@ bool CDKGSession::PreVerifyMessage(const CDKGPrematureCommitment& qc, bool& retB
         return false;
     }
 
-    for (size_t i = members.size(); i < params.size; i++) {
+    for (auto i = static_cast<int>(members.size()); i < params.size; i++) {
         if (qc.validMembers[i]) {
             retBan = true;
             logger.Batch("invalid validMembers bitset. bit %d should not be set", i);
@@ -1221,7 +1221,7 @@ std::vector<CFinalCommitment> CDKGSession::FinalizeCommitments()
     std::vector<CFinalCommitment> finalCommitments;
     for (const auto& p : commitmentsMap) {
         auto& cvec = p.second;
-        if (cvec.size() < params.minSize) {
+        if (cvec.size() < static_cast<size_t>(params.minSize)) {
             // commitment was signed by a minority
             continue;
         }
diff --git a/src/llmq/instantsend.cpp b/src/llmq/instantsend.cpp
index faf205ef95e2..05210febb045 100644
--- a/src/llmq/instantsend.cpp
+++ b/src/llmq/instantsend.cpp
@@ -192,7 +192,7 @@ std::unordered_map<uint256, CInstantSendLockPtr, StaticSaltedHasher> CInstantSen
         if (!it->GetKey(curKey) || std::get<0>(curKey) != DB_MINED_BY_HEIGHT_AND_HASH) {
             break;
         }
-        uint32_t nHeight = std::numeric_limits<uint32_t>::max() - be32toh(std::get<1>(curKey));
+        int32_t nHeight = std::numeric_limits<int32_t>::max() - be32toh(std::get<1>(curKey));
         if (nHeight > nUntilHeight) {
             break;
         }
@@ -236,7 +236,7 @@ void CInstantSendDb::RemoveArchivedInstantSendLocks(int nUntilHeight)
         if (!it->GetKey(curKey) || std::get<0>(curKey) != DB_ARCHIVED_BY_HEIGHT_AND_HASH) {
             break;
         }
-        uint32_t nHeight = std::numeric_limits<uint32_t>::max() - be32toh(std::get<1>(curKey));
+        int32_t nHeight = std::numeric_limits<int32_t>::max() - be32toh(std::get<1>(curKey));
         if (nHeight > nUntilHeight) {
             break;
         }
diff --git a/src/llmq/quorums.cpp b/src/llmq/quorums.cpp
index 93251829b069..89708764b637 100644
--- a/src/llmq/quorums.cpp
+++ b/src/llmq/quorums.cpp
@@ -690,7 +690,7 @@ void CQuorumManager::ProcessMessage(CNode* pFrom, const std::string& strCommand,
         // Check if request has ENCRYPTED_CONTRIBUTIONS data
         if (request.GetDataMask() & CQuorumDataRequest::ENCRYPTED_CONTRIBUTIONS) {
 
-            if (WITH_LOCK(pQuorum->cs, return pQuorum->quorumVvec->size() != pQuorum->params.threshold)) {
+            if (WITH_LOCK(pQuorum->cs, return pQuorum->quorumVvec->size() != static_cast<size_t>(pQuorum->params.threshold))) {
                 errorHandler("No valid quorum verification vector available", 0); // Don't bump score because we asked for it
                 return;
             }
diff --git a/src/llmq/signing_shares.cpp b/src/llmq/signing_shares.cpp
index 97ab5f747146..719defd3cc72 100644
--- a/src/llmq/signing_shares.cpp
+++ b/src/llmq/signing_shares.cpp
@@ -347,7 +347,7 @@ bool CSigSharesManager::ProcessMessageSigSesAnn(const CNode* pfrom, const CSigSe
 
 bool CSigSharesManager::VerifySigSharesInv(Consensus::LLMQType llmqType, const CSigSharesInv& inv)
 {
-    return inv.inv.size() == GetLLMQParams(llmqType).size;
+    return inv.inv.size() == static_cast<size_t>(GetLLMQParams(llmqType).size);
 }
 
 bool CSigSharesManager::ProcessMessageSigSharesInv(const CNode* pfrom, const CSigSharesInv& inv)
@@ -748,7 +748,7 @@ void CSigSharesManager::ProcessSigShare(const CSigShare& sigShare, const CConnma
         }
 
         size_t sigShareCount = sigShares.CountForSignHash(sigShare.GetSignHash());
-        if (sigShareCount >= quorum->params.threshold) {
+        if (sigShareCount >= static_cast<size_t>(quorum->params.threshold)) {
             canTryRecovery = true;
         }
     }
@@ -777,14 +777,14 @@ void CSigSharesManager::TryRecoverSig(const CQuorumCPtr& quorum, const uint256&
 
         sigSharesForRecovery.reserve((size_t) quorum->params.threshold);
         idsForRecovery.reserve((size_t) quorum->params.threshold);
-        for (auto it = sigSharesForSignHash->begin(); it != sigSharesForSignHash->end() && sigSharesForRecovery.size() < quorum->params.threshold; ++it) {
+        for (auto it = sigSharesForSignHash->begin(); it != sigSharesForSignHash->end() && sigSharesForRecovery.size() < static_cast<size_t>(quorum->params.threshold); ++it) {
             auto& sigShare = it->second;
             sigSharesForRecovery.emplace_back(sigShare.sigShare.Get());
             idsForRecovery.emplace_back(quorum->members[sigShare.quorumMember]->proTxHash);
         }
 
         // check if we can recover the final signature
-        if (sigSharesForRecovery.size() < quorum->params.threshold) {
+        if (sigSharesForRecovery.size() < static_cast<size_t>(quorum->params.threshold)) {
             return;
         }
     }
@@ -822,7 +822,7 @@ void CSigSharesManager::TryRecoverSig(const CQuorumCPtr& quorum, const uint256&
 
 CDeterministicMNCPtr CSigSharesManager::SelectMemberForRecovery(const CQuorumCPtr& quorum, const uint256 &id, int attempt)
 {
-    assert(attempt < quorum->members.size());
+    assert(static_cast<size_t>(attempt) < quorum->members.size());
 
     std::vector<std::pair<uint256, CDeterministicMNCPtr>> v;
     v.reserve(quorum->members.size());
diff --git a/src/masternode/utils.cpp b/src/masternode/utils.cpp
index cf0abaa9fae9..03d515ee2768 100644
--- a/src/masternode/utils.cpp
+++ b/src/masternode/utils.cpp
@@ -24,7 +24,7 @@ void CMasternodeUtils::ProcessMasternodeConnections(CConnman& connman)
 #endif // ENABLE_WALLET
 
     // Don't disconnect masternode connections when we have less then the desired amount of outbound nodes
-    int nonMasternodeCount = 0;
+    size_t nonMasternodeCount = 0;
     connman.ForEachNode(CConnman::AllNodes, [&](CNode* pnode) {
         if (!pnode->fInbound && !pnode->fFeeler && !pnode->m_manual_connection && !pnode->m_masternode_connection && !pnode->m_masternode_probe_connection) {
             nonMasternodeCount++;
diff --git a/src/prevector.h b/src/prevector.h
index 5b9cd0dfb3ea..fc793ec9d3aa 100644
--- a/src/prevector.h
+++ b/src/prevector.h
@@ -555,7 +555,7 @@ class prevector {
         // We know that internally the iterators are pointing to continues memory, so we can directly use the pointers here
         // This avoids internal use of std::copy and operator++ on the iterators and instead allows efficient memcpy/memmove
         if (std::is_trivially_constructible<T>::value) {
-            auto s = e - b;
+            size_t s = e - b;
             if (v.size() != s) {
                 v.resize(s);
             }
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index 0aa06dd1ab0b..0c20d36b91a7 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -1624,7 +1624,7 @@ std::vector<QFont::Weight> getSupportedWeights()
     return mapSupportedWeights[fontFamily];
 }
 
-QFont::Weight supportedWeightFromIndex(int nIndex)
+QFont::Weight supportedWeightFromIndex(size_t nIndex)
 {
     auto vecWeights = getSupportedWeights();
     assert(vecWeights.size() > nIndex);
@@ -1634,7 +1634,7 @@ QFont::Weight supportedWeightFromIndex(int nIndex)
 int supportedWeightToIndex(QFont::Weight weight)
 {
     auto vecWeights = getSupportedWeights();
-    for (int index = 0; index < vecWeights.size(); ++index) {
+    for (size_t index = 0; index < vecWeights.size(); ++index) {
         if (weight == vecWeights[index]) {
             return index;
         }
diff --git a/src/qt/guiutil.h b/src/qt/guiutil.h
index dd6b4a9d891e..407fe8b8913f 100644
--- a/src/qt/guiutil.h
+++ b/src/qt/guiutil.h
@@ -375,7 +375,7 @@ namespace GUIUtil
     /** Return supported weights for the current font family */
     std::vector<QFont::Weight> getSupportedWeights();
     /** Convert an index to a weight in the supported weights vector */
-    QFont::Weight supportedWeightFromIndex(int nIndex);
+    QFont::Weight supportedWeightFromIndex(size_t nIndex);
     /** Convert a weight to an index in the supported weights vector */
     int supportedWeightToIndex(QFont::Weight weight);
     /** Check if a weight is supported by the current font family */
diff --git a/src/rpc/masternode.cpp b/src/rpc/masternode.cpp
index 602f0b754aee..0d72324ee029 100644
--- a/src/rpc/masternode.cpp
+++ b/src/rpc/masternode.cpp
@@ -439,7 +439,7 @@ static UniValue masternode_payments(const JSONRPCRequest& request)
     // A temporary vector which is used to sort results properly (there is no "reverse" in/for UniValue)
     std::vector<UniValue> vecPayments;
 
-    while (vecPayments.size() < std::abs(nCount) && pindex != nullptr) {
+    while (vecPayments.size() < static_cast<size_t>(std::abs(nCount)) && pindex != nullptr) {
 
         CBlock block;
         if (!ReadBlockFromDisk(block, pindex, Params().GetConsensus())) {
diff --git a/src/serialize.h b/src/serialize.h
index 719c7890ee82..05f387823412 100644
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -509,12 +509,12 @@ void ReadFixedVarIntsBitSet(Stream& s, std::vector<bool>& vec, size_t size)
 
     int32_t last = -1;
     while(true) {
-        uint32_t offset = ReadVarInt<Stream, VarIntMode::DEFAULT, uint32_t>(s);
+        const int32_t offset = ReadVarInt<Stream, VarIntMode::DEFAULT, uint32_t>(s);
         if (offset == 0) {
             break;
         }
-        int32_t idx = last + offset;
-        if (idx >= size) {
+        const int32_t idx = last + offset;
+        if (static_cast<size_t>(idx) >= size) {
             throw std::ios_base::failure("out of bounds index");
         }
         if (last != -1 && idx <= last) {
diff --git a/src/stacktraces.cpp b/src/stacktraces.cpp
index e81a2bce8ec6..c3614e5a9f93 100644
--- a/src/stacktraces.cpp
+++ b/src/stacktraces.cpp
@@ -109,7 +109,7 @@ static std::string GetExeFileName()
         if (len < 0) {
             return "";
         }
-        if (len < buf.size()) {
+        if (len < static_cast<ssize_t>(buf.size())) {
             return std::string(buf.begin(), buf.begin() + len);
         }
         buf.resize(buf.size() * 2);
diff --git a/src/test/blockfilter_index_tests.cpp b/src/test/blockfilter_index_tests.cpp
index 76b5d79b27e6..cd7499eb3483 100644
--- a/src/test/blockfilter_index_tests.cpp
+++ b/src/test/blockfilter_index_tests.cpp
@@ -54,8 +54,8 @@ static bool CheckFilterLookups(BlockFilterIndex& filter_index, const CBlockIndex
     BOOST_CHECK(filter_index.LookupFilterHashRange(block_index->nHeight, block_index,
                                                    filter_hashes));
 
-    BOOST_CHECK_EQUAL(filters.size(), 1);
-    BOOST_CHECK_EQUAL(filter_hashes.size(), 1);
+    BOOST_CHECK_EQUAL(filters.size(), 1U);
+    BOOST_CHECK_EQUAL(filter_hashes.size(), 1U);
 
     BOOST_CHECK_EQUAL(filter.GetHash(), expected_filter.GetHash());
     BOOST_CHECK_EQUAL(filter_header, expected_filter.ComputeHeader(last_header));
@@ -256,8 +256,9 @@ BOOST_FIXTURE_TEST_CASE(blockfilter_index_initial_sync, TestChain100Setup)
     BOOST_CHECK(filter_index.LookupFilterRange(0, tip, filters));
     BOOST_CHECK(filter_index.LookupFilterHashRange(0, tip, filter_hashes));
 
-    BOOST_CHECK_EQUAL(filters.size(), tip->nHeight + 1);
-    BOOST_CHECK_EQUAL(filter_hashes.size(), tip->nHeight + 1);
+    assert(tip->nHeight >= 0);
+    BOOST_CHECK_EQUAL(filters.size(), tip->nHeight + 1U);
+    BOOST_CHECK_EQUAL(filter_hashes.size(), tip->nHeight + 1U);
 
     filters.clear();
     filter_hashes.clear();
diff --git a/src/test/blockfilter_tests.cpp b/src/test/blockfilter_tests.cpp
index 3006a009e0f2..8cee4c8f4eac 100644
--- a/src/test/blockfilter_tests.cpp
+++ b/src/test/blockfilter_tests.cpp
@@ -42,14 +42,14 @@ BOOST_AUTO_TEST_CASE(gcsfilter_test)
 BOOST_AUTO_TEST_CASE(gcsfilter_default_constructor)
 {
     GCSFilter filter;
-    BOOST_CHECK_EQUAL(filter.GetN(), 0);
-    BOOST_CHECK_EQUAL(filter.GetEncoded().size(), 1);
+    BOOST_CHECK_EQUAL(filter.GetN(), 0U);
+    BOOST_CHECK_EQUAL(filter.GetEncoded().size(), 1U);
 
     const GCSFilter::Params& params = filter.GetParams();
-    BOOST_CHECK_EQUAL(params.m_siphash_k0, 0);
-    BOOST_CHECK_EQUAL(params.m_siphash_k1, 0);
+    BOOST_CHECK_EQUAL(params.m_siphash_k0, 0U);
+    BOOST_CHECK_EQUAL(params.m_siphash_k1, 0U);
     BOOST_CHECK_EQUAL(params.m_P, 0);
-    BOOST_CHECK_EQUAL(params.m_M, 1);
+    BOOST_CHECK_EQUAL(params.m_M, 1U);
 }
 
 BOOST_AUTO_TEST_CASE(blockfilter_basic_test)
diff --git a/src/test/bloom_tests.cpp b/src/test/bloom_tests.cpp
index 9a34c4b26c5f..77a688892eb5 100644
--- a/src/test/bloom_tests.cpp
+++ b/src/test/bloom_tests.cpp
@@ -589,7 +589,7 @@ BOOST_AUTO_TEST_CASE(rolling_bloom)
             ++nHits;
     }
     // Expect about 100 hits
-    BOOST_CHECK_EQUAL(nHits, 75);
+    BOOST_CHECK_EQUAL(nHits, 75U);
 
     BOOST_CHECK(rb1.contains(data[DATASIZE-1]));
     rb1.reset();
@@ -617,7 +617,7 @@ BOOST_AUTO_TEST_CASE(rolling_bloom)
             ++nHits;
     }
     // Expect about 5 false positives
-    BOOST_CHECK_EQUAL(nHits, 6);
+    BOOST_CHECK_EQUAL(nHits, 6U);
 
     // last-1000-entry, 0.01% false positive:
     CRollingBloomFilter rb2(1000, 0.001);
diff --git a/src/test/flatfile_tests.cpp b/src/test/flatfile_tests.cpp
index 740d805ccedb..d53f800f6bf4 100644
--- a/src/test/flatfile_tests.cpp
+++ b/src/test/flatfile_tests.cpp
@@ -93,16 +93,16 @@ BOOST_AUTO_TEST_CASE(flatfile_allocate)
 
     bool out_of_space;
 
-    BOOST_CHECK_EQUAL(seq.Allocate(FlatFilePos(0, 0), 1, out_of_space), 100);
-    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 0))), 100);
+    BOOST_CHECK_EQUAL(seq.Allocate(FlatFilePos(0, 0), 1, out_of_space), 100U);
+    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 0))), 100U);
     BOOST_CHECK(!out_of_space);
 
-    BOOST_CHECK_EQUAL(seq.Allocate(FlatFilePos(0, 99), 1, out_of_space), 0);
-    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 99))), 100);
+    BOOST_CHECK_EQUAL(seq.Allocate(FlatFilePos(0, 99), 1, out_of_space), 0U);
+    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 99))), 100U);
     BOOST_CHECK(!out_of_space);
 
-    BOOST_CHECK_EQUAL(seq.Allocate(FlatFilePos(0, 99), 2, out_of_space), 101);
-    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 99))), 200);
+    BOOST_CHECK_EQUAL(seq.Allocate(FlatFilePos(0, 99), 2, out_of_space), 101U);
+    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 99))), 200U);
     BOOST_CHECK(!out_of_space);
 }
 
@@ -116,11 +116,11 @@ BOOST_AUTO_TEST_CASE(flatfile_flush)
 
     // Flush without finalize should not truncate file.
     seq.Flush(FlatFilePos(0, 1));
-    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 1))), 100);
+    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 1))), 100U);
 
     // Flush with finalize should truncate file.
     seq.Flush(FlatFilePos(0, 1), true);
-    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 1))), 1);
+    BOOST_CHECK_EQUAL(fs::file_size(seq.FileName(FlatFilePos(0, 1))), 1U);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/netbase_tests.cpp b/src/test/netbase_tests.cpp
index 2eaf260e210d..61378dc66f1c 100644
--- a/src/test/netbase_tests.cpp
+++ b/src/test/netbase_tests.cpp
@@ -520,7 +520,7 @@ BOOST_AUTO_TEST_CASE(netpermissions_test)
     BOOST_CHECK(NetWhitelistPermissions::TryParse("bloom,forcerelay,noban,relay,mempool@1.2.3.4/32", whitelistPermissions, error));
 
     const auto strings = NetPermissions::ToStrings(PF_ALL);
-    BOOST_CHECK_EQUAL(strings.size(), 5);
+    BOOST_CHECK_EQUAL(strings.size(), 5U);
     BOOST_CHECK(std::find(strings.begin(), strings.end(), "bloomfilter") != strings.end());
     BOOST_CHECK(std::find(strings.begin(), strings.end(), "forcerelay") != strings.end());
     BOOST_CHECK(std::find(strings.begin(), strings.end(), "relay") != strings.end());
diff --git a/src/test/random_tests.cpp b/src/test/random_tests.cpp
index 7c2fc4f2053b..2e0a3619eb61 100644
--- a/src/test/random_tests.cpp
+++ b/src/test/random_tests.cpp
@@ -128,7 +128,7 @@ BOOST_AUTO_TEST_CASE(shuffle_stat_test)
     }
     BOOST_CHECK(chi_score > 58.1411); // 99.9999% confidence interval
     BOOST_CHECK(chi_score < 210.275);
-    BOOST_CHECK_EQUAL(sum, 12000);
+    BOOST_CHECK_EQUAL(sum, 12000U);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/streams_tests.cpp b/src/test/streams_tests.cpp
index 11417a71882b..389d3de98c69 100644
--- a/src/test/streams_tests.cpp
+++ b/src/test/streams_tests.cpp
@@ -73,28 +73,28 @@ BOOST_AUTO_TEST_CASE(streams_vector_reader)
     std::vector<unsigned char> vch = {1, 255, 3, 4, 5, 6};
 
     VectorReader reader(SER_NETWORK, INIT_PROTO_VERSION, vch, 0);
-    BOOST_CHECK_EQUAL(reader.size(), 6);
+    BOOST_CHECK_EQUAL(reader.size(), 6U);
     BOOST_CHECK(!reader.empty());
 
     // Read a single byte as an unsigned char.
     unsigned char a;
     reader >> a;
     BOOST_CHECK_EQUAL(a, 1);
-    BOOST_CHECK_EQUAL(reader.size(), 5);
+    BOOST_CHECK_EQUAL(reader.size(), 5U);
     BOOST_CHECK(!reader.empty());
 
     // Read a single byte as a signed char.
     signed char b;
     reader >> b;
     BOOST_CHECK_EQUAL(b, -1);
-    BOOST_CHECK_EQUAL(reader.size(), 4);
+    BOOST_CHECK_EQUAL(reader.size(), 4U);
     BOOST_CHECK(!reader.empty());
 
     // Read a 4 bytes as an unsigned int.
     unsigned int c;
     reader >> c;
-    BOOST_CHECK_EQUAL(c, 100992003); // 3,4,5,6 in little-endian base-256
-    BOOST_CHECK_EQUAL(reader.size(), 0);
+    BOOST_CHECK_EQUAL(c, 100992003U); // 3,4,5,6 in little-endian base-256
+    BOOST_CHECK_EQUAL(reader.size(), 0U);
     BOOST_CHECK(reader.empty());
 
     // Reading after end of byte vector throws an error.
@@ -105,7 +105,7 @@ BOOST_AUTO_TEST_CASE(streams_vector_reader)
     VectorReader new_reader(SER_NETWORK, INIT_PROTO_VERSION, vch, 0);
     new_reader >> d;
     BOOST_CHECK_EQUAL(d, 67370753); // 1,255,3,4 in little-endian base-256
-    BOOST_CHECK_EQUAL(new_reader.size(), 2);
+    BOOST_CHECK_EQUAL(new_reader.size(), 2U);
     BOOST_CHECK(!new_reader.empty());
 
     // Reading after end of byte vector throws an error even if the reader is
@@ -148,14 +148,14 @@ BOOST_AUTO_TEST_CASE(bitstream_reader_writer)
     BOOST_CHECK_EQUAL(serialized_int2, (uint16_t)0x1072); // NOTE: Serialized as LE
 
     BitStreamReader<CDataStream> bit_reader(data_copy);
-    BOOST_CHECK_EQUAL(bit_reader.Read(1), 0);
-    BOOST_CHECK_EQUAL(bit_reader.Read(2), 2);
-    BOOST_CHECK_EQUAL(bit_reader.Read(3), 6);
-    BOOST_CHECK_EQUAL(bit_reader.Read(4), 11);
-    BOOST_CHECK_EQUAL(bit_reader.Read(5), 1);
-    BOOST_CHECK_EQUAL(bit_reader.Read(6), 32);
-    BOOST_CHECK_EQUAL(bit_reader.Read(7), 7);
-    BOOST_CHECK_EQUAL(bit_reader.Read(16), 30497);
+    BOOST_CHECK_EQUAL(bit_reader.Read(1), 0U);
+    BOOST_CHECK_EQUAL(bit_reader.Read(2), 2U);
+    BOOST_CHECK_EQUAL(bit_reader.Read(3), 6U);
+    BOOST_CHECK_EQUAL(bit_reader.Read(4), 11U);
+    BOOST_CHECK_EQUAL(bit_reader.Read(5), 1U);
+    BOOST_CHECK_EQUAL(bit_reader.Read(6), 32U);
+    BOOST_CHECK_EQUAL(bit_reader.Read(7), 7U);
+    BOOST_CHECK_EQUAL(bit_reader.Read(16), 30497U);
     BOOST_CHECK_THROW(bit_reader.Read(8), std::ios_base::failure);
 }
 
@@ -248,7 +248,7 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file)
     BOOST_CHECK_EQUAL(i, 1);
 
     // After reading bytes 0 and 1, we're positioned at 2.
-    BOOST_CHECK_EQUAL(bf.GetPos(), 2);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 2U);
 
     // Rewind to offset 0, ok (within the 10 byte window).
     BOOST_CHECK(bf.SetPos(0));
@@ -275,18 +275,18 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file)
     // The default argument removes the limit completely.
     BOOST_CHECK(bf.SetLimit());
     // The read position should still be at 3 (no change).
-    BOOST_CHECK_EQUAL(bf.GetPos(), 3);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 3U);
 
     // Read from current offset, 3, forward until position 10.
     for (uint8_t j = 3; j < 10; ++j) {
         bf >> i;
         BOOST_CHECK_EQUAL(i, j);
     }
-    BOOST_CHECK_EQUAL(bf.GetPos(), 10);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 10U);
 
     // We're guaranteed (just barely) to be able to rewind to zero.
     BOOST_CHECK(bf.SetPos(0));
-    BOOST_CHECK_EQUAL(bf.GetPos(), 0);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 0U);
     bf >> i;
     BOOST_CHECK_EQUAL(i, 0);
 
@@ -296,12 +296,12 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file)
     BOOST_CHECK(bf.SetPos(10));
     bf >> i;
     BOOST_CHECK_EQUAL(i, 10);
-    BOOST_CHECK_EQUAL(bf.GetPos(), 11);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 11U);
 
     // Now it's only guaranteed that we can rewind to offset 1
     // (current read position, 11, minus rewind amount, 10).
     BOOST_CHECK(bf.SetPos(1));
-    BOOST_CHECK_EQUAL(bf.GetPos(), 1);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 1U);
     bf >> i;
     BOOST_CHECK_EQUAL(i, 1);
 
@@ -315,7 +315,7 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file)
             BOOST_CHECK_EQUAL(a[j], 11 + j);
         }
     }
-    BOOST_CHECK_EQUAL(bf.GetPos(), 40);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 40U);
 
     // We've read the entire file, the next read should throw.
     try {
@@ -329,11 +329,11 @@ BOOST_AUTO_TEST_CASE(streams_buffered_file)
     BOOST_CHECK(bf.eof());
 
     // Still at offset 40, we can go back 10, to 30.
-    BOOST_CHECK_EQUAL(bf.GetPos(), 40);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 40U);
     BOOST_CHECK(bf.SetPos(30));
     bf >> i;
     BOOST_CHECK_EQUAL(i, 30);
-    BOOST_CHECK_EQUAL(bf.GetPos(), 31);
+    BOOST_CHECK_EQUAL(bf.GetPos(), 31U);
 
     // We're too far to rewind to position zero.
     BOOST_CHECK(!bf.SetPos(0));
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index afbe6a089a7e..45afb26e01aa 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -1278,24 +1278,24 @@ BOOST_AUTO_TEST_CASE(test_tracked_vector)
     BOOST_CHECK(t3.origin == &t3);
 
     auto v1 = Vector(t1);
-    BOOST_CHECK_EQUAL(v1.size(), 1);
+    BOOST_CHECK_EQUAL(v1.size(), 1U);
     BOOST_CHECK(v1[0].origin == &t1);
     BOOST_CHECK_EQUAL(v1[0].copies, 1);
 
     auto v2 = Vector(std::move(t2));
-    BOOST_CHECK_EQUAL(v2.size(), 1);
+    BOOST_CHECK_EQUAL(v2.size(), 1U);
     BOOST_CHECK(v2[0].origin == &t2);
     BOOST_CHECK_EQUAL(v2[0].copies, 0);
 
     auto v3 = Vector(t1, std::move(t2));
-    BOOST_CHECK_EQUAL(v3.size(), 2);
+    BOOST_CHECK_EQUAL(v3.size(), 2U);
     BOOST_CHECK(v3[0].origin == &t1);
     BOOST_CHECK(v3[1].origin == &t2);
     BOOST_CHECK_EQUAL(v3[0].copies, 1);
     BOOST_CHECK_EQUAL(v3[1].copies, 0);
 
     auto v4 = Vector(std::move(v3[0]), v3[1], std::move(t3));
-    BOOST_CHECK_EQUAL(v4.size(), 3);
+    BOOST_CHECK_EQUAL(v4.size(), 3U);
     BOOST_CHECK(v4[0].origin == &t1);
     BOOST_CHECK(v4[1].origin == &t2);
     BOOST_CHECK(v4[2].origin == &t3);
@@ -1304,7 +1304,7 @@ BOOST_AUTO_TEST_CASE(test_tracked_vector)
     BOOST_CHECK_EQUAL(v4[2].copies, 0);
 
     auto v5 = Cat(v1, v4);
-    BOOST_CHECK_EQUAL(v5.size(), 4);
+    BOOST_CHECK_EQUAL(v5.size(), 4U);
     BOOST_CHECK(v5[0].origin == &t1);
     BOOST_CHECK(v5[1].origin == &t1);
     BOOST_CHECK(v5[2].origin == &t2);
@@ -1315,7 +1315,7 @@ BOOST_AUTO_TEST_CASE(test_tracked_vector)
     BOOST_CHECK_EQUAL(v5[3].copies, 1);
 
     auto v6 = Cat(std::move(v1), v3);
-    BOOST_CHECK_EQUAL(v6.size(), 3);
+    BOOST_CHECK_EQUAL(v6.size(), 3U);
     BOOST_CHECK(v6[0].origin == &t1);
     BOOST_CHECK(v6[1].origin == &t1);
     BOOST_CHECK(v6[2].origin == &t2);
@@ -1324,7 +1324,7 @@ BOOST_AUTO_TEST_CASE(test_tracked_vector)
     BOOST_CHECK_EQUAL(v6[2].copies, 1);
 
     auto v7 = Cat(v2, std::move(v4));
-    BOOST_CHECK_EQUAL(v7.size(), 4);
+    BOOST_CHECK_EQUAL(v7.size(), 4U);
     BOOST_CHECK(v7[0].origin == &t2);
     BOOST_CHECK(v7[1].origin == &t1);
     BOOST_CHECK(v7[2].origin == &t2);
@@ -1335,7 +1335,7 @@ BOOST_AUTO_TEST_CASE(test_tracked_vector)
     BOOST_CHECK_EQUAL(v7[3].copies, 0);
 
     auto v8 = Cat(std::move(v2), std::move(v3));
-    BOOST_CHECK_EQUAL(v8.size(), 3);
+    BOOST_CHECK_EQUAL(v8.size(), 3U);
     BOOST_CHECK(v8[0].origin == &t2);
     BOOST_CHECK(v8[1].origin == &t1);
     BOOST_CHECK(v8[2].origin == &t2);
diff --git a/src/test/util_threadnames_tests.cpp b/src/test/util_threadnames_tests.cpp
index 32a51e34e1b8..dc6a0c4ecab4 100644
--- a/src/test/util_threadnames_tests.cpp
+++ b/src/test/util_threadnames_tests.cpp
@@ -61,7 +61,7 @@ BOOST_AUTO_TEST_CASE(util_threadnames_test_rename_threaded)
 
     std::set<std::string> names = RenameEnMasse(100);
 
-    BOOST_CHECK_EQUAL(names.size(), 100);
+    BOOST_CHECK_EQUAL(names.size(), 100U);
 
     // Names "test_thread.[n]" should exist for n = [0, 99]
     for (int i = 0; i < 100; ++i) {
diff --git a/src/util/system.cpp b/src/util/system.cpp
index 79d26815fa3a..33a3d5c70f13 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -1235,7 +1235,7 @@ void RenameThreadPool(ctpl::thread_pool& tp, const char* baseName)
         // `doneCnt` should be at least `futures.size()` if tp size was increased (for whatever reason),
         // or at least `tp.size()` if tp size was decreased and queue was cleared
         // (which can happen on `stop()` if we were not fast enough to get all jobs to their threads).
-    } while (doneCnt < futures.size() && doneCnt < tp.size());
+    } while (doneCnt < static_cast<int64_t>(futures.size()) && doneCnt < tp.size());
 
     cond->notify_all();
 
diff --git a/src/validation.cpp b/src/validation.cpp
index 1d5f35dcae6f..0969d75c437f 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -146,7 +146,7 @@ bool fPruneMode = false;
 bool fRequireStandard = true;
 bool fCheckBlockIndex = false;
 bool fCheckpointsEnabled = DEFAULT_CHECKPOINTS_ENABLED;
-size_t nCoinCacheUsage = 5000 * 300;
+int64_t nCoinCacheUsage = 5000 * 300;
 uint64_t nPruneTarget = 0;
 int64_t nMaxTipAge = DEFAULT_MAX_TIP_AGE;
 
@@ -4653,7 +4653,7 @@ bool CVerifyDB::VerifyDB(const CChainParams& chainparams, CCoinsView *coinsview,
             }
         }
         // check level 3: check for inconsistencies during memory-only disconnect of tip blocks
-        if (nCheckLevel >= 3 && (coins.DynamicMemoryUsage() + ::ChainstateActive().CoinsTip().DynamicMemoryUsage()) <= nCoinCacheUsage) {
+        if (nCheckLevel >= 3 && (coins.DynamicMemoryUsage() + ::ChainstateActive().CoinsTip().DynamicMemoryUsage()) <= static_cast<size_t>(nCoinCacheUsage)) {
             assert(coins.GetBestBlock() == pindex->GetBlockHash());
             DisconnectResult res = ::ChainstateActive().DisconnectBlock(block, pindex, coins);
             if (res == DISCONNECT_FAILED) {
diff --git a/src/validation.h b/src/validation.h
index 949b07c9533a..3763cbaec655 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -143,7 +143,7 @@ extern bool g_parallel_script_checks;
 extern bool fRequireStandard;
 extern bool fCheckBlockIndex;
 extern bool fCheckpointsEnabled;
-extern size_t nCoinCacheUsage;
+extern int64_t nCoinCacheUsage;
 /** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */
 extern CFeeRate minRelayTxFee;
 /** Absolute maximum transaction fee (in duffs) used by wallet and mempool (rejects high fee in sendrawtransaction) */
diff --git a/src/wallet/test/coinjoin_tests.cpp b/src/wallet/test/coinjoin_tests.cpp
index 4a662ba61675..116cdb19e6e9 100644
--- a/src/wallet/test/coinjoin_tests.cpp
+++ b/src/wallet/test/coinjoin_tests.cpp
@@ -98,7 +98,7 @@ class CTransactionBuilderTestSetup : public TestChain100Setup
             BOOST_CHECK(wallet->CommitTransaction(tx, {}, {}, reserveKey, state));
             AddTxToChain(tx->GetHash());
             for (size_t n = 0; n < tx->vout.size(); ++n) {
-                if (nChangePosRet != -1 && n == nChangePosRet) {
+                if (nChangePosRet != -1 && static_cast<int>(n) == nChangePosRet) {
                     // Skip the change output to only return the requested coins
                     continue;
                 }
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index d19fb198301c..4b55e592fe70 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -592,9 +592,8 @@ class CreateTransactionTestSetup : public TestChain100Setup
         it->second.SetMerkleBranch(::ChainActive().Tip()->GetBlockHash(), 1);
 
         std::vector<COutPoint> vecOutpoints;
-        size_t n;
-        for (n = 0; n < tx->vout.size(); ++n) {
-            if (nChangePosRet != -1 && n == nChangePosRet) {
+        for (size_t n = 0; n < tx->vout.size(); ++n) {
+            if (nChangePosRet != -1 && static_cast<int>(n) == nChangePosRet) {
                 // Skip the change output to only return the requested coins
                 continue;
             }
@@ -628,7 +627,7 @@ BOOST_FIXTURE_TEST_CASE(CreateTransactionTest, CreateTransactionTestSetup)
             {13, {{100001, true}}}
         };
         assert(mapTestCases.size() == mapExpected.size());
-        for (int i = 0; i < mapTestCases.size(); ++i) {
+        for (size_t i = 0; i < mapTestCases.size(); ++i) {
             if (!CreateTransaction(mapTestCases.at(i), mapExpected.at(i).first, mapExpected.at(i).second)) {
                 std::cout << strprintf("CreateTransactionTest failed at: %d - %d\n", nTestId, i) << std::endl;
             }
@@ -853,12 +852,12 @@ BOOST_FIXTURE_TEST_CASE(CreateTransactionTest, CreateTransactionTestSetup)
 
         // Just to create nCount output recipes to use in tests below
         std::vector<std::pair<CAmount, bool>> vecOutputEntries{{5000, false}};
-        auto createOutputEntries = [&](int nCount) {
+        auto createOutputEntries = [&](size_t nCount) {
             while (vecOutputEntries.size() <= nCount) {
                 vecOutputEntries.push_back(vecOutputEntries.back());
             }
             if (vecOutputEntries.size() > nCount) {
-                int nDiff = vecOutputEntries.size() - nCount;
+                size_t nDiff = vecOutputEntries.size() - nCount;
                 vecOutputEntries.erase(vecOutputEntries.begin(), vecOutputEntries.begin() + nDiff);
             }
         };
@@ -938,9 +937,9 @@ BOOST_FIXTURE_TEST_CASE(select_coins_grouped_by_addresses, ListCoinsTestingSetup
     {
         LOCK(wallet->cs_wallet);
         const auto& conflicts = wallet->GetConflicts(tx2->GetHash());
-        BOOST_CHECK_EQUAL(conflicts.size(), 2);
-        BOOST_CHECK_EQUAL(conflicts.count(tx1->GetHash()), 1);
-        BOOST_CHECK_EQUAL(conflicts.count(tx2->GetHash()), 1);
+        BOOST_CHECK_EQUAL(conflicts.size(), 2U);
+        BOOST_CHECK_EQUAL(conflicts.count(tx1->GetHash()), 1U);
+        BOOST_CHECK_EQUAL(conflicts.count(tx2->GetHash()), 1U);
     }
 
     // Committed tx is the one that should be marked as "conflicting".
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 30f1f38031fb..44855639e0c8 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -3373,7 +3373,7 @@ bool CWallet::SelectCoinsGroupedByAddresses(std::vector<CompactTallyItem>& vecTa
             if(!(mine & filter)) continue;
 
             auto itTallyItem = mapTally.find(txdest);
-            if (nMaxOupointsPerAddress != -1 && itTallyItem != mapTally.end() && itTallyItem->second.vecInputCoins.size() >= nMaxOupointsPerAddress) continue;
+            if (nMaxOupointsPerAddress != -1 && itTallyItem != mapTally.end() && itTallyItem->second.vecInputCoins.size() >= static_cast<size_t>(nMaxOupointsPerAddress)) continue;
 
             if(IsSpent(*locked_chain, outpoint.hash, i) || IsLockedCoin(outpoint.hash, i)) continue;