diff --git a/src/hash.h b/src/hash.h
index 485655a00..128680f0f 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -225,6 +225,55 @@ public:
     }
 };
 
+/** An optimized and dangerous writer stream (for serialization) that computes a 256-bit Verus hash without the normal
+ * safety checks. Do not try to write more than 1488 bytes to this hash writer. */
+class CVerusMiningHashWriter
+{
+public:
+    union hwBuf {
+        unsigned char charBuf[1488];
+        int32_t i32a[522];
+        hwBuf()
+        {
+            memset(charBuf, 0, sizeof(charBuf));
+        }
+    };
+    hwBuf buf;
+    int nPos;
+    int nType;
+    int nVersion;
+
+    CVerusMiningHashWriter(int nTypeIn, int nVersionIn, int pos = 0) : buf()
+    {
+        nPos = pos;
+        nType = nTypeIn;
+        nVersion = nVersionIn;
+    }
+
+    CVerusMiningHashWriter& write(const char *pch, size_t size) {
+        if ((nPos + size) <= sizeof(buf.charBuf))
+        {
+            memcpy(&(buf.charBuf[nPos]), pch, size);
+            nPos += size;
+        }
+        return (*this);
+    }
+
+    // does not invalidate the object for modification and further hashing
+    uint256 GetHash() {
+        uint256 result;
+        CVerusHash::Hash((unsigned char*)&result, buf.charBuf, nPos);
+        return result;
+    }
+
+    template<typename T>
+    CVerusMiningHashWriter& operator<<(const T& obj) {
+        // Serialize to this stream
+        ::Serialize(*this, obj, nType, nVersion);
+        return (*this);
+    }
+};
+
 /** Compute the 256-bit hash of an object's serialization. */
 template<typename T>
 uint256 SerializeHash(const T& obj, int nType=SER_GETHASH, int nVersion=PROTOCOL_VERSION)
@@ -243,6 +292,15 @@ uint256 SerializeVerusHash(const T& obj, int nType=SER_GETHASH, int nVersion=PRO
     return ss.GetHash();
 }
 
+/** Compute the 256-bit Verus hash of an object's serialization. */
+template<typename T>
+uint256 SerializeVerusMiningHash(const T& obj, int nType=SER_GETHASH, int nVersion=PROTOCOL_VERSION)
+{
+    CVerusMiningHashWriter ss = CVerusMiningHashWriter(nType, nVersion);
+    ss << obj;
+    return ss.GetHash();
+}
+
 unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash);
 
 void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64]);
diff --git a/src/main.cpp b/src/main.cpp
index 48d319f7f..bef0d296d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -910,7 +910,7 @@ unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& in
 bool ContextualCheckCoinbaseTransaction(const CTransaction& tx, const int nHeight)
 {
     // if time locks are on, ensure that this coin base is time locked exactly as it should be
-    if ((uint64_t)(tx.GetValueOut()) >= ASSETCHAINS_TIMELOCKGTE)
+    if (((uint64_t)(tx.GetValueOut()) >= ASSETCHAINS_TIMELOCKGTE) || (nHeight >= 31680) && komodo_ac_block_subsidy(nHeight) >= ASSETCHAINS_TIMELOCKGTE)
     {
         CScriptID scriptHash;
 
diff --git a/src/miner.cpp b/src/miner.cpp
index ef41e6db0..63b8a9b93 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -1148,17 +1148,20 @@ void static BitcoinMiner_noeq()
             {
                 arith_uint256 arNonce = UintToArith256(pblock->nNonce);
 
+                CVerusMiningHashWriter ss = CVerusMiningHashWriter(SER_GETHASH, PROTOCOL_VERSION);
+                ss << *((CBlockHeader *)pblock);
+
                 // for speed check 16 mega hash at a time
                 for (int i = 0; i < 0x1000000; i++)
                 {
                     solutionTargetChecks.increment();
 
                     // Update nNonce
-                    *((unsigned char *)&(pblock->nNonce)) = i & 0xff;
-                    *(((unsigned char *)&(pblock->nNonce))+1) = (i >> 8) & 0xff;
-                    *(((unsigned char *)&(pblock->nNonce))+2) = (i >> 16) & 0xff;
+                    ss.buf.charBuf[108] = *((unsigned char *)&(pblock->nNonce)) = i & 0xff;
+                    ss.buf.charBuf[109] = *(((unsigned char *)&(pblock->nNonce))+1) = (i >> 8) & 0xff;
+                    ss.buf.charBuf[110] = *(((unsigned char *)&(pblock->nNonce))+2) = (i >> 16) & 0xff;
 
-                    if ( UintToArith256(pblock->GetHash()) <= hashTarget )
+                    if ( UintToArith256(ss.GetHash()) <= hashTarget )
                     {
                         SetThreadPriority(THREAD_PRIORITY_NORMAL);
 
diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index fc937ec3d..3d8b080c0 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -27,6 +27,12 @@ uint256 CBlockHeader::GetVerusHash() const
         return SerializeVerusHash(*this);
 }
 
+uint256 CBlockHeader::GetVerusMiningHash() const
+{
+    // no check for genesis block and use the optimized hash
+    return SerializeVerusMiningHash(*this);
+}
+
 void CBlockHeader::SetSHA256DHash()
 {
     CBlockHeader::hashFunction = &CBlockHeader::GetSHA256DHash;
diff --git a/src/primitives/block.h b/src/primitives/block.h
index 6a45648f3..97e9c1c07 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -84,6 +84,8 @@ public:
     uint256 GetVerusHash() const;
     static void SetVerusHash();
 
+    uint256 GetVerusMiningHash() const;
+
     int64_t GetBlockTime() const
     {
         return (int64_t)nTime;
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 8a8e30763..e1cca1878 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1053,7 +1053,7 @@ int32_t CWallet::VerusStakeTransaction(CMutableTransaction &txNew, uint32_t &bnT
     if (!VerusSelectStakeOutput(hashResult, stakeSource, voutNum, tipindex->nHeight + 1, target) ||
         !Solver(stakeSource.vout[voutNum].scriptPubKey, whichType, vSolutions))
     {
-        LogPrintf("No eligible staking transaction found");
+        LogPrintf("No eligible staking transaction found\n");
         return 0;
     }