diff --git a/src/wallet/rpchushwallet.cpp b/src/wallet/rpchushwallet.cpp
index 85574b7c7..74f0c6702 100644
--- a/src/wallet/rpchushwallet.cpp
+++ b/src/wallet/rpchushwallet.cpp
@@ -148,12 +148,16 @@ void zsTxSpendsToJSON(const CWalletTx& wtx, UniValue& spends, CAmount& totalSpen
       const SpendDescription& spendDesc = wtx.vShieldedSpend[i];
       UniValue obj(UniValue::VOBJ);
 
-      SaplingOutPoint op = pwalletMain->mapSaplingNullifiersToNotes[spendDesc.nullifier];
+      std::map<uint256, SaplingOutPoint>::const_iterator nfIt = pwalletMain->mapSaplingNullifiersToNotes.find(spendDesc.nullifier);
 
-      if (pwalletMain->IsSaplingNullifierFromMe(spendDesc.nullifier)) {
-        const CWalletTx* parent = pwalletMain->GetWalletTx(pwalletMain->mapSaplingNullifiersToNotes[spendDesc.nullifier].hash);
+      // Same test as IsSaplingNullifierFromMe(), but find() so a read-only RPC never inserts into wallet maps.
+      if (nfIt != pwalletMain->mapSaplingNullifiersToNotes.end() && pwalletMain->mapWallet.count(nfIt->second.hash)) {
+        const SaplingOutPoint op = nfIt->second;
+        const CWalletTx* parent = pwalletMain->GetWalletTx(op.hash);
+        mapSaplingNoteData_t::const_iterator ndIt = parent->mapSaplingNoteData.find(op);
+        if (ndIt == parent->mapSaplingNoteData.end()) continue;  // stale entry: old code inserted an empty note that never decrypts
         const OutputDescription& output = parent->vShieldedOutput[op.n];
-        const SaplingNoteData& nd = pwalletMain->mapWallet[pwalletMain->mapSaplingNullifiersToNotes[spendDesc.nullifier].hash].mapSaplingNoteData[op];
+        const SaplingNoteData& nd = ndIt->second;
         auto pt = libzcash::SaplingNotePlaintext::decrypt(output.encCiphertext,nd.ivk,output.ephemeralKey,output.cm);
 
         if (pt) {