diff --git a/src/miner.cpp b/src/miner.cpp
index ee85a52eb..227ba999b 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -279,11 +279,16 @@ CBlockTemplate* CreateNewBlock(CPubKey _pk,const CScript& _scriptPubKeyIn, int32
         vecPriority.reserve(mempool.mapTx.size() + 1);
 
         //fprintf(stderr,"%s: going to add txs from mempool\n", __func__);
-        // now add transactions from the mem pool
+        // now add transactions from the mempool
         int32_t Notarizations = 0; uint64_t txvalue;
+        uint32_t large_zins  = 0;                  // number of ztxs with large number of inputs in block
+        uint32_t large_zouts = 0;                  // number of ztxs with large number of outputs in block
+        const uint32_t LARGE_ZINS_MAX        = 1;  // max ztxs with large zins per block
+        const uint32_t LARGE_ZOUTS_MAX       = 1;  // max ztxs with large zouts per block
+        const uint32_t LARGE_ZINS_THRESHOLD  = 50; // min number of zins to be considered large
+        const uint32_t LARGE_ZOUTS_THRESHOLD = 10; // min number of zouts to be considered large
         for (CTxMemPool::indexed_transaction_set::iterator mi = mempool.mapTx.begin();
-             mi != mempool.mapTx.end(); ++mi)
-        {
+             mi != mempool.mapTx.end(); ++mi) {
             const CTransaction& tx = mi->GetTx();
 
             int64_t nLockTimeCutoff = (STANDARD_LOCKTIME_VERIFY_FLAGS & LOCKTIME_MEDIAN_TIME_PAST)
@@ -466,6 +471,18 @@ CBlockTemplate* CreateNewBlock(CPubKey _pk,const CScript& _scriptPubKeyIn, int32
             // fprintf(stderr,"%s: compared first tx from priority queue\n", __func__);
             vecPriority.pop_back();
 
+            if(tx.vShieldedSpend.size() >= LARGE_ZINS_THRESHOLD && large_zins >= LARGE_ZINS_MAX) {
+                LogPrintf("%s: skipping ztx %s with %d zins because there are already %d ztxs with large zins\n",
+                    __func__, tx.GetHash().ToString().c_str(), tx.vShieldedSpend.size(), LARGE_ZINS_MAX);
+                continue;
+            }
+
+            if(tx.vShieldedOutput.size() >= LARGE_ZOUTS_THRESHOLD && large_zouts >= LARGE_ZOUTS_MAX) {
+                LogPrintf("%s: skipping ztx %s with %d zouts because there are already %d ztxs with large zouts\n",
+                    __func__, tx.GetHash().ToString().c_str(), tx.vShieldedOutput.size(), LARGE_ZOUTS_MAX);
+                continue;
+            }
+
             // Size limits
             unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
             // fprintf(stderr,"%s: nTxSize = %u\n", __func__, nTxSize);
@@ -576,6 +593,18 @@ CBlockTemplate* CreateNewBlock(CPubKey _pk,const CScript& _scriptPubKeyIn, int32
             nBlockSigOps += nTxSigOps;
             nFees += nTxFees;
 
+            if(tx.vShieldedOutput.size() >= LARGE_ZOUTS_THRESHOLD) {
+                large_zouts++;
+                LogPrintf("%s: txid=%s has large zouts=%d (%d large zouts in block)\n", __func__, tx.GetHash().ToString().c_str(),
+                    tx.vShieldedOutput.size(), large_zouts );
+            }
+
+            if(tx.vShieldedSpend.size() >= LARGE_ZINS_THRESHOLD) {
+                large_zins++;
+                LogPrintf("%s: txid=%s has large zins=%d (%d large zouts in block)\n", __func__, tx.GetHash().ToString().c_str(),
+                    tx.vShieldedSpend.size(), large_zins );
+            }
+
             if (fPrintPriority)
             {
                 LogPrintf("priority %.1f fee %s txid %s\n",dPriority, feeRate.ToString(), tx.GetHash().ToString());