diff --git a/src/rpc/budget.cpp b/src/rpc/budget.cpp
index 9e6f900f97fda..74c7bd3a9d525 100644
--- a/src/rpc/budget.cpp
+++ b/src/rpc/budget.cpp
@@ -162,8 +162,9 @@ UniValue preparebudget(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_WALLET_ERROR, res.ToString());
 
     // Store proposal name as a comment
-    assert(pwallet->mapWallet.count(wtx->GetHash()));
-    pwallet->mapWallet.at(wtx->GetHash()).SetComment("Proposal: " + strProposalName);
+    auto it = pwallet->mapWallet.find(wtx->GetHash());
+    assert(it != pwallet->mapWallet.end());
+    it->second.SetComment("Proposal: " + strProposalName);
 
     return wtx->GetHash().ToString();
 }
diff --git a/src/sapling/saplingscriptpubkeyman.cpp b/src/sapling/saplingscriptpubkeyman.cpp
index 75f371951d7d2..1b2593314f372 100644
--- a/src/sapling/saplingscriptpubkeyman.cpp
+++ b/src/sapling/saplingscriptpubkeyman.cpp
@@ -37,10 +37,9 @@ void SaplingScriptPubKeyMan::UpdateSaplingNullifierNoteMapForBlock(const CBlock
     LOCK(wallet->cs_wallet);
 
     for (const auto& tx : pblock->vtx) {
-        const uint256& hash = tx->GetHash();
-        bool txIsOurs = wallet->mapWallet.count(hash);
-        if (txIsOurs) {
-            UpdateSaplingNullifierNoteMapWithTx(wallet->mapWallet.at(hash));
+        auto it = wallet->mapWallet.find(tx->GetHash());
+        if (it != wallet->mapWallet.end()) {
+            UpdateSaplingNullifierNoteMapWithTx(it->second);
         }
     }
 }
@@ -746,8 +745,9 @@ CAmount SaplingScriptPubKeyMan::GetDebit(const CTransaction& tx, const isminefil
             // If we have the spend nullifier, it means that this input is ours.
             // The transaction (and decrypted note data) has been added to the wallet.
             const SaplingOutPoint& op = it->second;
-            assert(wallet->mapWallet.count(op.hash));
-            const auto& wtx = wallet->mapWallet.at(op.hash);
+            auto wit = wallet->mapWallet.find(op.hash);
+            assert(wit != wallet->mapWallet.end());
+            const auto& wtx = wit->second;
             assert(wtx.mapSaplingNoteData.count(op));
             const auto& nd = wtx.mapSaplingNoteData.at(op);
             assert(nd.IsMyNote());        // todo: Add watch only check.
@@ -820,10 +820,11 @@ void SaplingScriptPubKeyMan::GetSaplingNoteWitnesses(const std::vector<SaplingOu
     Optional<uint256> rt;
     int i = 0;
     for (SaplingOutPoint note : notes) {
-        if (wallet->mapWallet.count(note.hash) &&
-            wallet->mapWallet.at(note.hash).mapSaplingNoteData.count(note) &&
-            wallet->mapWallet.at(note.hash).mapSaplingNoteData[note].witnesses.size() > 0) {
-            witnesses[i] = wallet->mapWallet.at(note.hash).mapSaplingNoteData[note].witnesses.front();
+        auto it = wallet->mapWallet.find(note.hash);
+        if (it != wallet->mapWallet.end() &&
+            it->second.mapSaplingNoteData.count(note) &&
+            it->second.mapSaplingNoteData[note].witnesses.size() > 0) {
+            witnesses[i] = it->second.mapSaplingNoteData[note].witnesses.front();
             if (!rt) {
                 rt = witnesses[i]->root();
             } else {
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index d90b68a97be9f..4d0501ff61cf3 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1094,12 +1094,13 @@ static UniValue ShieldSendManyTo(CWallet * const pwallet,
 
     // add comments
     const uint256& txHash = uint256S(txid);
-    assert(pwallet->mapWallet.count(txHash));
+    auto it = pwallet->mapWallet.find(txHash);
+    assert(it != pwallet->mapWallet.end());
     if (!commentStr.empty()) {
-        pwallet->mapWallet.at(txHash).mapValue["comment"] = commentStr;
+        it->second.mapValue["comment"] = commentStr;
     }
     if (!toStr.empty()) {
-        pwallet->mapWallet.at(txHash).mapValue["to"] = toStr;
+        it->second.mapValue["to"] = toStr;
     }
 
     return txid;
@@ -1532,9 +1533,10 @@ UniValue viewshieldtransaction(const JSONRPCRequest& request)
     hash.SetHex(request.params[0].get_str());
 
     UniValue entry(UniValue::VOBJ);
-    if (!pwallet->mapWallet.count(hash))
+    auto it = pwallet->mapWallet.find(hash);
+    if (it == pwallet->mapWallet.end())
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid or non-wallet transaction id");
-    const CWalletTx& wtx = pwallet->mapWallet.at(hash);
+    const CWalletTx& wtx = it->second;
 
     if (!wtx.tx->IsShieldedTx()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid transaction, no shield data available");
@@ -2807,8 +2809,9 @@ UniValue listreceivedbyshieldaddress(const JSONRPCRequest& request)
         int index = -1;
         int64_t time = 0;
 
-        if (pwallet->mapWallet.count(entry.op.hash)) {
-            const CWalletTx& wtx = pwallet->mapWallet.at(entry.op.hash);
+        auto it = pwallet->mapWallet.find(entry.op.hash);
+        if (it != pwallet->mapWallet.end()) {
+            const CWalletTx& wtx = it->second;
             if (!wtx.m_confirm.hashBlock.IsNull())
                 height = mapBlockIndex[wtx.m_confirm.hashBlock]->nHeight;
             index = wtx.m_confirm.nIndex;