diff --git a/src/masternode.cpp b/src/masternode.cpp
index 8993c4da6..9fb3aa770 100644
--- a/src/masternode.cpp
+++ b/src/masternode.cpp
@@ -189,17 +189,11 @@ void CMasternode::Check(bool forceCheck)
 {
     if (ShutdownRequested()) return;
 
-    const Consensus::Params& consensus = Params().GetConsensus();
-
-    // todo: add LOCK(cs) but be careful with the AcceptableInputs() below that requires cs_main.
-
-    if (!forceCheck && (GetTime() - lastTimeChecked < MASTERNODE_CHECK_SECONDS)) return;
-    lastTimeChecked = GetTime();
-
-
     //once spent, stop doing the checks
     if (activeState == MASTERNODE_VIN_SPENT) return;
 
+    if (!forceCheck && (GetTime() - lastTimeChecked < MASTERNODE_CHECK_SECONDS)) return;
+    lastTimeChecked = GetTime();
 
     if (!IsPingedWithin(MASTERNODE_REMOVAL_SECONDS)) {
         activeState = MASTERNODE_REMOVE;
@@ -216,7 +210,10 @@ void CMasternode::Check(bool forceCheck)
         return;
     }
 
-    if (!unitTest && lastTimeChecked - lastTimeCollateralChecked > MINUTE_IN_SECONDS) {
+    if (!unitTest && 
+        forceCheck && 
+        lastTimeChecked - lastTimeCollateralChecked > MINUTE_IN_SECONDS
+    ) {
         lastTimeCollateralChecked = lastTimeChecked;
         CValidationState state;
         CMutableTransaction tx = CMutableTransaction();
@@ -235,6 +232,8 @@ void CMasternode::Check(bool forceCheck)
             }
         }
 
+        const auto& consensus = Params().GetConsensus();
+
         // ----------- burn address scanning -----------
         if (!consensus.mBurnAddresses.empty()) {
 
@@ -684,7 +683,7 @@ bool CMasternodeBroadcast::CheckAndUpdate(int& nDos)
         //take the newest entry
         LogPrint(BCLog::MASTERNODE, "mnb - Got updated entry for %s\n", vin.prevout.ToStringShort());
         if (pmn->UpdateFromNewBroadcast((*this))) {
-            pmn->Check();
+            pmn->Check(true);
             if (pmn->IsEnabled()) Relay();
         }
         masternodeSync.AddedMasternodeList(GetHash());
diff --git a/src/masternodeman.cpp b/src/masternodeman.cpp
index a4203a6fb..d06de3b1b 100644
--- a/src/masternodeman.cpp
+++ b/src/masternodeman.cpp
@@ -265,18 +265,26 @@ void CMasternodeMan::AskForMN(CNode* pnode, const CTxIn& vin)
     mWeAskedForMasternodeListEntry[vin.prevout] = askAgain;
 }
 
-void CMasternodeMan::Check()
+void CMasternodeMan::Check(bool forceCheck)
 {
-    LOCK2(cs_main, cs);
+    if(forceCheck) {
+        LOCK2(cs_main, cs);
 
-    for (auto mn : vMasternodes) {
-        mn->Check();
+        for (auto mn : vMasternodes) {
+            mn->Check(forceCheck);
+        }
+    } else {
+        LOCK(cs);
+
+        for (auto mn : vMasternodes) {
+            mn->Check();
+        }
     }
 }
 
 void CMasternodeMan::CheckAndRemove(bool forceExpiredRemoval)
 {
-    Check();
+    Check(true);
 
     LOCK(cs);
 
@@ -442,7 +450,7 @@ int CMasternodeMan::CountEnabled()
 {
     int i = 0;
 
-    LOCK2(cs_main, cs);
+    LOCK(cs);
 
     for (auto mn : vMasternodes) {
         mn->Check();
@@ -455,7 +463,7 @@ int CMasternodeMan::CountEnabled()
 
 void CMasternodeMan::CountNetworks(int& ipv4, int& ipv6, int& onion)
 {
-    LOCK2(cs_main, cs);
+    LOCK(cs);
 
     for (auto mn : vMasternodes) {
         mn->Check();
@@ -561,7 +569,7 @@ CMasternode* CMasternodeMan::GetNextMasternodeInQueueForPayment(int nBlockHeight
     vEligibleTxIns.clear();
     int nMnCount = 0;
     {
-        LOCK2(cs_main, cs);
+        LOCK(cs);
 
         nMnCount = CountEnabled();
         for (auto mn : vMasternodes) {
@@ -656,7 +664,7 @@ CMasternode* CMasternodeMan::GetCurrentMasterNode(int mod, int64_t nBlockHeight)
     int64_t score = 0;
     CMasternode* winner = NULL;
 
-    LOCK2(cs_main, cs);
+    LOCK(cs);
 
     // scan for winner
     for (auto mn : vMasternodes) {
@@ -692,7 +700,7 @@ int CMasternodeMan::GetMasternodeRank(const CTxIn& vin, int64_t nBlockHeight)
     uint256 hash;
     if (!GetBlockHash(hash, nBlockHeight)) return defaultValue;
 
-    LOCK2(cs_main, cs);
+    LOCK(cs);
 
     // scan for winner
     for (auto mn : vMasternodes) {
@@ -1002,10 +1010,7 @@ void ThreadCheckMasternodes()
             MilliSleep(1000);
             boost::this_thread::interruption_point();
             // try to sync from all available nodes, one step at a time
-            {
-                LOCK(cs_main);
-                masternodeSync.Process();
-            }
+            masternodeSync.Process();
 
             if (masternodeSync.IsBlockchainSynced()) {
                 c++;
diff --git a/src/masternodeman.h b/src/masternodeman.h
index 4f9a2ff63..68145e0b9 100644
--- a/src/masternodeman.h
+++ b/src/masternodeman.h
@@ -159,7 +159,7 @@ class CMasternodeMan
     void AskForMN(CNode* pnode, const CTxIn& vin);
 
     /// Check all Masternodes
-    void Check();
+    void Check(bool forceCheck = false);
 
     /// Check all Masternodes and remove inactive
     void CheckAndRemove(bool forceExpiredRemoval = false);
diff --git a/src/miner.cpp b/src/miner.cpp
index 25b98b1ab..db61fa8a9 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -209,8 +209,11 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn, CWallet* pwallet,
     // Collect memory pool transactions into the block
     CAmount nFees = 0;
 
+    LOCK(cs_main);
+
     {
-        LOCK2(cs_main, mempool.cs);
+        LOCK(mempool.cs);
+
         CCoinsViewCache view(pcoinsTip);
 
         // Priority order to process transactions
@@ -408,13 +411,13 @@ CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn, CWallet* pwallet,
                 return nullptr;
             }
         }
+    }
 
-        CValidationState state;
-        if (!TestBlockValidity(state, *pblock, pindexPrev, false, false)) {
-            LogPrintf("CreateNewBlock() : TestBlockValidity failed\n");
-            mempool.clear();
-            return nullptr;
-        }
+    CValidationState state;
+    if (!TestBlockValidity(state, *pblock, pindexPrev, false, false)) {
+        LogPrintf("CreateNewBlock() : TestBlockValidity failed\n");
+        mempool.clear();
+        return nullptr;
     }
 
     return pblocktemplate.release();