diff --git a/src/masternode-payments.cpp b/src/masternode-payments.cpp
index a700e9e884745..a3231981b84e4 100644
--- a/src/masternode-payments.cpp
+++ b/src/masternode-payments.cpp
@@ -161,11 +161,11 @@ std::string CMasternodePaymentWinner::GetStrMessage() const
     return vinMasternode.prevout.ToStringShort() + std::to_string(nBlockHeight) + HexStr(payee);
 }
 
-bool CMasternodePaymentWinner::IsValid(CNode* pnode, std::string& strError)
+bool CMasternodePaymentWinner::IsValid(CNode* pnode, std::string& strError, int chainHeight)
 {
     int n = mnodeman.GetMasternodeRank(vinMasternode, nBlockHeight - 100);
-
-    if (n < 1 || n > MNPAYMENTS_SIGNATURES_TOTAL) {
+    bool guard = Params().GetConsensus().NetworkUpgradeActive(chainHeight, Consensus::UPGRADE_V5_3);
+    if ((guard && n < 1) || n > MNPAYMENTS_SIGNATURES_TOTAL) {
         //It's common to have masternodes mistakenly think they are in the top 10
         // We don't want to print all of these messages, or punish them unless they're way off
         if (n > MNPAYMENTS_SIGNATURES_TOTAL * 2) {
@@ -176,6 +176,12 @@ bool CMasternodePaymentWinner::IsValid(CNode* pnode, std::string& strError)
         return false;
     }
 
+    // Must be a P2PKH
+    if (guard && !payee.IsPayToPublicKeyHash()) {
+        LogPrint(BCLog::MASTERNODE, "%s - payee must be a P2PKH\n", __func__);
+        return false;
+    }
+
     return true;
 }
 
@@ -219,9 +225,9 @@ bool IsBlockValueValid(int nHeight, CAmount& nExpectedValue, CAmount nMinted, CA
         }
     }
 
-    // !todo: remove after V6 enforcement and default it to true
-    const bool isV6UpgradeEnforced = consensus.NetworkUpgradeActive(nHeight, Consensus::UPGRADE_V6_0);
-    return (!isV6UpgradeEnforced || nMinted >= 0) && nMinted <= nExpectedValue;
+    // !todo: remove after V5.3 enforcement and default it to true
+    const bool isUpgradeEnforced = consensus.NetworkUpgradeActive(nHeight, Consensus::UPGRADE_V5_3);
+    return (!isUpgradeEnforced || nMinted >= 0) && nMinted <= nExpectedValue;
 }
 
 bool IsBlockPayeeValid(const CBlock& block, const CBlockIndex* pindexPrev)
@@ -326,7 +332,7 @@ bool CMasternodePayments::GetLegacyMasternodeTxOut(int nHeight, std::vector<CTxO
     if (!GetBlockPayee(nHeight, payee)) {
         //no masternode detected
         const Consensus::Params& consensus = Params().GetConsensus();
-        const uint256& hash = consensus.NetworkUpgradeActive(nHeight, Consensus::UPGRADE_V6_0) ?
+        const uint256& hash = consensus.NetworkUpgradeActive(nHeight, Consensus::UPGRADE_V5_3) ?
                               mnodeman.GetHashAtHeight(nHeight - 1) : consensus.hashGenesisBlock;
         MasternodeRef winningNode = mnodeman.GetCurrentMasterNode(hash);
         if (winningNode) {
@@ -457,7 +463,7 @@ void CMasternodePayments::ProcessMessageMasternodePayments(CNode* pfrom, std::st
         }
 
         std::string strError = "";
-        if (!winner.IsValid(pfrom, strError)) {
+        if (!winner.IsValid(pfrom, strError, nHeight)) {
             // if(strError != "") LogPrint(BCLog::MASTERNODE,"mnw - invalid message - %s\n", strError);
             return;
         }
diff --git a/src/masternode-payments.h b/src/masternode-payments.h
index 187b945fc0390..93c176f7a69b7 100644
--- a/src/masternode-payments.h
+++ b/src/masternode-payments.h
@@ -177,7 +177,7 @@ class CMasternodePaymentWinner : public CSignedMessage
     std::string GetStrMessage() const override;
     CTxIn GetVin() const { return vinMasternode; };
 
-    bool IsValid(CNode* pnode, std::string& strError);
+    bool IsValid(CNode* pnode, std::string& strError, int chainHeight);
     void Relay();
 
     void AddPayee(const CScript& payeeIn)
diff --git a/src/masternode.cpp b/src/masternode.cpp
index 6f8c917086188..4b244326c713a 100644
--- a/src/masternode.cpp
+++ b/src/masternode.cpp
@@ -62,6 +62,13 @@ int MasternodeRemovalSeconds()
     return Params().IsRegTestNet() ? MASTERNODE_REMOVAL_SECONDS_REGTEST : MASTERNODE_REMOVAL_SECONDS;
 }
 
+// Used for sigTime < maxTimeWindow
+int64_t GetMaxTimeWindow(int chainHeight)
+{
+    bool isV5_3 = Params().GetConsensus().NetworkUpgradeActive(chainHeight, Consensus::UPGRADE_V5_3);
+    return GetAdjustedTime() + (isV5_3 ? (60 * 2) : (60 * 60));
+}
+
 
 CMasternode::CMasternode() :
         CSignedMessage()
@@ -136,7 +143,7 @@ std::string CMasternode::GetStrMessage() const
 //
 // When a new masternode broadcast is sent, update our information
 //
-bool CMasternode::UpdateFromNewBroadcast(CMasternodeBroadcast& mnb)
+bool CMasternode::UpdateFromNewBroadcast(CMasternodeBroadcast& mnb, int chainHeight)
 {
     if (mnb.sigTime > sigTime) {
         // TODO: lock cs. Need to be careful as mnb.lastPing.CheckAndUpdate locks cs_main internally.
@@ -147,7 +154,7 @@ bool CMasternode::UpdateFromNewBroadcast(CMasternodeBroadcast& mnb)
         protocolVersion = mnb.protocolVersion;
         addr = mnb.addr;
         int nDoS = 0;
-        if (mnb.lastPing.IsNull() || (!mnb.lastPing.IsNull() && mnb.lastPing.CheckAndUpdate(nDoS, false))) {
+        if (mnb.lastPing.IsNull() || (!mnb.lastPing.IsNull() && mnb.lastPing.CheckAndUpdate(nDoS, chainHeight, false))) {
             lastPing = mnb.lastPing;
             mnodeman.mapSeenMasternodePing.emplace(lastPing.GetHash(), lastPing);
         }
@@ -393,10 +400,10 @@ bool CMasternodeBroadcast::CheckDefaultPort(CService service, std::string& strEr
     return true;
 }
 
-bool CMasternodeBroadcast::CheckAndUpdate(int& nDos)
+bool CMasternodeBroadcast::CheckAndUpdate(int& nDos, int nChainHeight)
 {
     // make sure signature isn't in the future (past is OK)
-    if (sigTime > GetAdjustedTime() + 60 * 60) {
+    if (sigTime > GetMaxTimeWindow(nChainHeight)) {
         LogPrint(BCLog::MASTERNODE,"mnb - Signature rejected, too far into the future %s\n", vin.prevout.hash.ToString());
         nDos = 1;
         return false;
@@ -444,7 +451,7 @@ bool CMasternodeBroadcast::CheckAndUpdate(int& nDos)
         return false;
 
     // incorrect ping or its sigTime
-    if(lastPing.IsNull() || !lastPing.CheckAndUpdate(nDos, false, true)) {
+    if(lastPing.IsNull() || !lastPing.CheckAndUpdate(nDos, nChainHeight, false, true)) {
         return false;
     }
 
@@ -470,7 +477,7 @@ bool CMasternodeBroadcast::CheckAndUpdate(int& nDos)
     if (pmn->pubKeyCollateralAddress == pubKeyCollateralAddress && !pmn->IsBroadcastedWithin(MasternodeBroadcastSeconds())) {
         //take the newest entry
         LogPrint(BCLog::MASTERNODE,"mnb - Got updated entry for %s\n", vin.prevout.hash.ToString());
-        if (pmn->UpdateFromNewBroadcast((*this))) {
+        if (pmn->UpdateFromNewBroadcast((*this), nChainHeight)) {
             if (pmn->IsEnabled()) Relay();
         }
         masternodeSync.AddedMasternodeList(GetHash());
@@ -491,7 +498,7 @@ bool CMasternodeBroadcast::CheckInputsAndAdd(int nChainHeight, int& nDoS)
     }
 
     // incorrect ping or its sigTime
-    if(lastPing.IsNull() || !lastPing.CheckAndUpdate(nDoS, false, true)) {
+    if(lastPing.IsNull() || !lastPing.CheckAndUpdate(nDoS, nChainHeight, false, true)) {
         return false;
     }
 
@@ -589,9 +596,9 @@ std::string CMasternodePing::GetStrMessage() const
     return vin.ToString() + blockHash.ToString() + std::to_string(sigTime);
 }
 
-bool CMasternodePing::CheckAndUpdate(int& nDos, bool fRequireAvailable, bool fCheckSigTimeOnly)
+bool CMasternodePing::CheckAndUpdate(int& nDos, int nChainHeight, bool fRequireAvailable, bool fCheckSigTimeOnly)
 {
-    if (sigTime > GetAdjustedTime() + 60 * 60) {
+    if (sigTime > GetMaxTimeWindow(nChainHeight)) {
         LogPrint(BCLog::MNPING,"%s: Signature rejected, too far into the future %s\n", __func__, vin.prevout.hash.ToString());
         nDos = 30;
         return false;
diff --git a/src/masternode.h b/src/masternode.h
index 8dc5812b88f5e..0e717a10ae384 100644
--- a/src/masternode.h
+++ b/src/masternode.h
@@ -58,7 +58,7 @@ class CMasternodePing : public CSignedMessage
     const CTxIn GetVin() const { return vin; };
     bool IsNull() const { return blockHash.IsNull() || vin.prevout.IsNull(); }
 
-    bool CheckAndUpdate(int& nDos, bool fRequireAvailable = true, bool fCheckSigTimeOnly = false);
+    bool CheckAndUpdate(int& nDos, int nChainHeight, bool fRequireAvailable = true, bool fCheckSigTimeOnly = false);
     void Relay();
 
     CMasternodePing& operator=(const CMasternodePing& other) = default;
@@ -156,7 +156,7 @@ class CMasternode : public CSignedMessage
         Unserialize(s);
     }
 
-    bool UpdateFromNewBroadcast(CMasternodeBroadcast& mnb);
+    bool UpdateFromNewBroadcast(CMasternodeBroadcast& mnb, int chainHeight);
 
     CMasternode::state GetActiveState() const;
 
@@ -243,7 +243,7 @@ class CMasternodeBroadcast : public CMasternode
     CMasternodeBroadcast(CService newAddr, CTxIn newVin, CPubKey newPubkey, CPubKey newPubkey2, int protocolVersionIn, const CMasternodePing& _lastPing);
     CMasternodeBroadcast(const CMasternode& mn);
 
-    bool CheckAndUpdate(int& nDoS);
+    bool CheckAndUpdate(int& nDoS, int nChainHeight);
     bool CheckInputsAndAdd(int chainHeight, int& nDos);
 
     uint256 GetHash() const;
diff --git a/src/masternodeman.cpp b/src/masternodeman.cpp
index 441d44695c142..8fd10a466eb33 100644
--- a/src/masternodeman.cpp
+++ b/src/masternodeman.cpp
@@ -713,7 +713,7 @@ int CMasternodeMan::ProcessMNBroadcast(CNode* pfrom, CMasternodeBroadcast& mnb)
     }
 
     int nDoS = 0;
-    if (!mnb.CheckAndUpdate(nDoS)) {
+    if (!mnb.CheckAndUpdate(nDoS, GetBestHeight())) {
         return nDoS;
     }
 
@@ -747,7 +747,7 @@ int CMasternodeMan::ProcessMNPing(CNode* pfrom, CMasternodePing& mnp)
     if (mapSeenMasternodePing.count(mnpHash)) return 0; //seen
 
     int nDoS = 0;
-    if (mnp.CheckAndUpdate(nDoS)) return 0;
+    if (mnp.CheckAndUpdate(nDoS, GetBestHeight())) return 0;
 
     if (nDoS > 0) {
         // if anything significant failed, mark that node
@@ -894,7 +894,7 @@ void CMasternodeMan::UpdateMasternodeList(CMasternodeBroadcast& mnb)
         CMasternode mn(mnb);
         Add(mn);
     } else {
-        pmn->UpdateFromNewBroadcast(mnb);
+        pmn->UpdateFromNewBroadcast(mnb, GetBestHeight());
     }
 }
 
diff --git a/src/test/budget_tests.cpp b/src/test/budget_tests.cpp
index 076b183a4fff0..b8044d89d8b2c 100644
--- a/src/test/budget_tests.cpp
+++ b/src/test/budget_tests.cpp
@@ -136,7 +136,7 @@ BOOST_FIXTURE_TEST_CASE(block_value_undermint, RegTestingSetup)
     CAmount nBudgetAmtRet = 0;
     // under-minting blocks are invalid after v6
     BOOST_CHECK(IsBlockValueValid(nHeight, nExpectedRet, -1, nBudgetAmtRet));
-    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_V6_0, Consensus::NetworkUpgrade::ALWAYS_ACTIVE);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_V5_3, Consensus::NetworkUpgrade::ALWAYS_ACTIVE);
     BOOST_CHECK(!IsBlockValueValid(nHeight, nExpectedRet, -1, nBudgetAmtRet));
 }