diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -4092,7 +4092,7 @@
         }
     }
 
-    CBlockIndex *stopBlock = pwallet->ScanForWalletTransactions(
+    const CBlockIndex *stopBlock = pwallet->ScanForWalletTransactions(
         pindexStart, pindexStop, reserver, true);
     if (!stopBlock) {
         if (pwallet->IsAbortingRescan()) {
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -1062,10 +1062,11 @@
     BlockDisconnected(const std::shared_ptr<const CBlock> &pblock) override;
     int64_t RescanFromTime(int64_t startTime,
                            const WalletRescanReserver &reserver, bool update);
-    CBlockIndex *ScanForWalletTransactions(CBlockIndex *pindexStart,
-                                           CBlockIndex *pindexStop,
-                                           const WalletRescanReserver &reserver,
-                                           bool fUpdate = false);
+    const CBlockIndex *
+    ScanForWalletTransactions(const CBlockIndex *const pindexStart,
+                              const CBlockIndex *const pindexStop,
+                              const WalletRescanReserver &reserver,
+                              bool fUpdate = false);
     void TransactionRemovedFromMempool(const CTransactionRef &ptx) override;
     void ReacceptWalletTransactions();
     void ResendWalletTransactions(int64_t nBestBlockTime,
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1827,8 +1827,8 @@
  * the main chain after to the addition of any new keys you want to detect
  * transactions for.
  */
-CBlockIndex *CWallet::ScanForWalletTransactions(
-    CBlockIndex *pindexStart, CBlockIndex *pindexStop,
+const CBlockIndex *CWallet::ScanForWalletTransactions(
+    const CBlockIndex *const pindexStart, const CBlockIndex *const pindexStop,
     const WalletRescanReserver &reserver, bool fUpdate) {
     int64_t nNow = GetTime();
 
@@ -1837,8 +1837,8 @@
         assert(pindexStop->nHeight >= pindexStart->nHeight);
     }
 
-    CBlockIndex *pindex = pindexStart;
-    CBlockIndex *ret = nullptr;
+    const CBlockIndex *pindex = pindexStart;
+    const CBlockIndex *ret = nullptr;
 
     if (pindex) {
         WalletLogPrintf("Rescan started from block %d...\n", pindex->nHeight);