diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 20426eace..d1a89ed91 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -51,12 +51,13 @@ struct COrphanTx {
     NodeId fromPeer;
     int64_t nTimeExpire;
 };
-std::map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(cs_main);
-std::map<COutPoint, std::set<std::map<uint256, COrphanTx>::iterator, IteratorComparator>> mapOrphanTransactionsByPrev GUARDED_BY(cs_main);
-void EraseOrphansFor(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
+static CCriticalSection g_cs_orphans;
+std::map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(g_cs_orphans);
+std::map<COutPoint, std::set<std::map<uint256, COrphanTx>::iterator, IteratorComparator>> mapOrphanTransactionsByPrev GUARDED_BY(g_cs_orphans);
+void EraseOrphansFor(NodeId peer);
 
-static size_t vExtraTxnForCompactIt = 0;
-static std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUARDED_BY(cs_main);
+static size_t vExtraTxnForCompactIt GUARDED_BY(g_cs_orphans) = 0;
+static std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUARDED_BY(g_cs_orphans);
 
 static const uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL; // SHA256("main address relay")[0:8]
 
@@ -127,7 +128,7 @@ namespace {
     int g_outbound_peers_with_protect_from_disconnect = 0;
 
     /** When our tip was last updated. */
-    int64_t g_last_tip_update = 0;
+    std::atomic<int64_t> g_last_tip_update(0);
 
     /** Relay map, protected by cs_main. */
     typedef std::map<uint256, CTransactionRef> MapRelay;
@@ -631,7 +632,7 @@ bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
 // mapOrphanTransactions
 //
 
-void AddToCompactExtraTransactions(const CTransactionRef& tx) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+void AddToCompactExtraTransactions(const CTransactionRef& tx) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans)
 {
     size_t max_extra_txn = gArgs.GetArg("-blockreconstructionextratxn", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN);
     if (max_extra_txn <= 0)
@@ -642,7 +643,7 @@ void AddToCompactExtraTransactions(const CTransactionRef& tx) EXCLUSIVE_LOCKS_RE
     vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % max_extra_txn;
 }
 
-bool AddOrphanTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+bool AddOrphanTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans)
 {
     const uint256& hash = tx->GetHash();
     if (mapOrphanTransactions.count(hash))
@@ -675,7 +676,7 @@ bool AddOrphanTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRE
     return true;
 }
 
-int static EraseOrphanTx(uint256 hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+int static EraseOrphanTx(uint256 hash) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans)
 {
     std::map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.find(hash);
     if (it == mapOrphanTransactions.end())
@@ -695,6 +696,7 @@ int static EraseOrphanTx(uint256 hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
 
 void EraseOrphansFor(NodeId peer)
 {
+    LOCK(g_cs_orphans);
     int nErased = 0;
     std::map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
     while (iter != mapOrphanTransactions.end())
@@ -709,8 +711,10 @@ void EraseOrphansFor(NodeId peer)
 }
 
 
-unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
 {
+    LOCK(g_cs_orphans);
+
     unsigned int nEvicted = 0;
     static int64_t nNextSweep;
     int64_t nNow = GetTime();
@@ -804,7 +808,7 @@ PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn, CScheduler &schedu
 }
 
 void PeerLogicValidation::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex, const std::vector<CTransactionRef>& vtxConflicted) {
-    LOCK(cs_main);
+    LOCK(g_cs_orphans);
 
     std::vector<uint256> vOrphanErase;
 
@@ -971,9 +975,13 @@ bool static AlreadyHave(const CInv& inv) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
                 recentRejects->reset();
             }
 
+            {
+                LOCK(g_cs_orphans);
+                if (mapOrphanTransactions.count(inv.hash)) return true;
+            }
+
             return recentRejects->contains(inv.hash) ||
                    mempool.exists(inv.hash) ||
-                   mapOrphanTransactions.count(inv.hash) ||
                    pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 0)) || // Best effort: only try output 0 and 1
                    pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 1));
         }
@@ -2101,7 +2109,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
         CInv inv(MSG_TX, tx.GetHash());
         pfrom->AddInventoryKnown(inv);
 
-        LOCK(cs_main);
+        LOCK2(cs_main, g_cs_orphans);
 
         bool fMissingInputs = false;
         CValidationState state;
@@ -2324,7 +2332,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
         bool fBlockReconstructed = false;
 
         {
-        LOCK(cs_main);
+        LOCK2(cs_main, g_cs_orphans);
         // If AcceptBlockHeader returned true, it set pindex
         assert(pindex);
         UpdateBlockAvailability(pfrom->GetId(), pindex->GetBlockHash());