diff --git a/src/bench/CMakeLists.txt b/src/bench/CMakeLists.txt
--- a/src/bench/CMakeLists.txt
+++ b/src/bench/CMakeLists.txt
@@ -50,6 +50,7 @@
 	gcs_filter.cpp
 	lockedpool.cpp
 	mempool_eviction.cpp
+	mempool_stress.cpp
 	merkle_root.cpp
 	prevector.cpp
 	rollingbloom.cpp
diff --git a/src/bench/mempool_stress.cpp b/src/bench/mempool_stress.cpp
new file mode 100644
--- /dev/null
+++ b/src/bench/mempool_stress.cpp
@@ -0,0 +1,93 @@
+// Copyright (c) 2011-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <bench/bench.h>
+#include <policy/policy.h>
+#include <random.h>
+#include <txmempool.h>
+
+#include <vector>
+
+static void AddTx(const CTransactionRef &tx, CTxMemPool &pool)
+    EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs) {
+    int64_t nTime = 0;
+    unsigned int nHeight = 1;
+    bool spendsCoinbase = false;
+    unsigned int sigOpCost = 4;
+    LockPoints lp;
+    pool.addUnchecked(CTxMemPoolEntry(tx, 1000 * SATOSHI, nTime, nHeight,
+                                      spendsCoinbase, sigOpCost, lp));
+}
+
+struct Available {
+    CTransactionRef ref;
+    size_t vin_left{0};
+    size_t tx_count;
+    Available(CTransactionRef &_ref, size_t _tx_count)
+        : ref(_ref), tx_count(_tx_count) {}
+};
+
+static void ComplexMemPool(benchmark::State &state) {
+    FastRandomContext det_rand{true};
+    std::vector<Available> available_coins;
+    std::vector<CTransactionRef> ordered_coins;
+    // Create some base transactions
+    size_t tx_counter = 1;
+    for (auto x = 0; x < 100; ++x) {
+        CMutableTransaction tx = CMutableTransaction();
+        tx.vin.resize(1);
+        tx.vin[0].scriptSig = CScript() << CScriptNum(tx_counter);
+        tx.vout.resize(det_rand.randrange(10) + 2);
+        for (auto &out : tx.vout) {
+            out.scriptPubKey = CScript() << CScriptNum(tx_counter) << OP_EQUAL;
+            out.nValue = 10 * COIN;
+        }
+        ordered_coins.emplace_back(MakeTransactionRef(tx));
+        available_coins.emplace_back(ordered_coins.back(), tx_counter++);
+    }
+    for (auto x = 0; x < 800 && !available_coins.empty(); ++x) {
+        CMutableTransaction tx = CMutableTransaction();
+        size_t n_ancestors = det_rand.randrange(10) + 1;
+        for (size_t ancestor = 0;
+             ancestor < n_ancestors && !available_coins.empty(); ++ancestor) {
+            size_t idx = det_rand.randrange(available_coins.size());
+            Available coin = available_coins[idx];
+            TxId txid = coin.ref->GetId();
+            // biased towards taking just one ancestor, but maybe more
+            size_t n_to_take =
+                det_rand.randrange(2) == 0
+                    ? 1
+                    : 1 + det_rand.randrange(coin.ref->vout.size() -
+                                             coin.vin_left);
+            for (size_t i = 0; i < n_to_take; ++i) {
+                tx.vin.emplace_back();
+                tx.vin.back().prevout = COutPoint(txid, coin.vin_left++);
+                tx.vin.back().scriptSig = CScript() << coin.tx_count;
+            }
+            if (coin.vin_left == coin.ref->vin.size()) {
+                coin = available_coins.back();
+                available_coins.pop_back();
+            }
+            tx.vout.resize(det_rand.randrange(10) + 2);
+            for (auto &out : tx.vout) {
+                out.scriptPubKey = CScript()
+                                   << CScriptNum(tx_counter) << OP_EQUAL;
+                out.nValue = 10 * COIN;
+            }
+        }
+        ordered_coins.emplace_back(MakeTransactionRef(tx));
+        available_coins.emplace_back(ordered_coins.back(), tx_counter++);
+    }
+    CTxMemPool pool;
+    LOCK2(cs_main, pool.cs);
+    while (state.KeepRunning()) {
+        for (auto &tx : ordered_coins) {
+            AddTx(tx, pool);
+        }
+        pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4);
+        pool.TrimToSize(GetVirtualTransactionSize(*ordered_coins.front()));
+    }
+}
+
+BENCHMARK(ComplexMemPool, 1);
diff --git a/src/psbt.h b/src/psbt.h
--- a/src/psbt.h
+++ b/src/psbt.h
@@ -328,9 +328,6 @@
     bool AddInput(const CTxIn &txin, PSBTInput &psbtin);
     bool AddOutput(const CTxOut &txout, const PSBTOutput &psbtout);
     PartiallySignedTransaction() {}
-    PartiallySignedTransaction(const PartiallySignedTransaction &psbt_in)
-        : tx(psbt_in.tx), inputs(psbt_in.inputs), outputs(psbt_in.outputs),
-          unknown(psbt_in.unknown) {}
     explicit PartiallySignedTransaction(const CMutableTransaction &txIn);
     /**
      * Finds the UTXO for a given input index