diff --git a/src/index/base.cpp b/src/index/base.cpp
index 0e76bafeca..a5c0cc29c9 100644
--- a/src/index/base.cpp
+++ b/src/index/base.cpp
@@ -144,9 +144,44 @@ static const CBlockIndex* NextSyncBlock(const CBlockIndex* pindex_prev, CChain&
         return pindex;
     }
 
+    // Since block is not in the chain, return the next block in the chain AFTER the last common ancestor.
+    // Caller will be responsible for rewinding back to the common ancestor.
     return chain.Next(chain.FindFork(pindex_prev));
 }
 
+bool BaseIndex::ProcessBlock(const CBlockIndex* pindex, const CBlock* block_data)
+{
+    interfaces::BlockInfo block_info = kernel::MakeBlockInfo(pindex, block_data);
+
+    CBlock block;
+    if (!block_data) { // disk lookup if block data wasn't provided
+        if (!m_chainstate->m_blockman.ReadBlock(block, *pindex)) {
+            FatalErrorf("%s: Failed to read block %s from disk",
+                        __func__, pindex->GetBlockHash().ToString());
+            return false;
+        }
+        block_info.data = █
+    }
+
+    CBlockUndo block_undo;
+    if (CustomOptions().connect_undo_data) {
+        if (pindex->nHeight > 0 && !m_chainstate->m_blockman.ReadBlockUndo(block_undo, *pindex)) {
+            FatalErrorf("%s: Failed to read undo block data %s from disk",
+                        __func__, pindex->GetBlockHash().ToString());
+            return false;
+        }
+        block_info.undo_data = &block_undo;
+    }
+
+    if (!CustomAppend(block_info)) {
+        FatalErrorf("%s: Failed to write block %s to index database",
+                    __func__, pindex->GetBlockHash().ToString());
+        return false;
+    }
+
+    return true;
+}
+
 void BaseIndex::Sync()
 {
     const CBlockIndex* pindex = m_best_block_index.load();
@@ -192,20 +227,7 @@ void BaseIndex::Sync()
             pindex = pindex_next;
 
 
-            CBlock block;
-            interfaces::BlockInfo block_info = kernel::MakeBlockInfo(pindex);
-            if (!m_chainstate->m_blockman.ReadBlock(block, *pindex)) {
-                FatalErrorf("%s: Failed to read block %s from disk",
-                           __func__, pindex->GetBlockHash().ToString());
-                return;
-            } else {
-                block_info.data = █
-            }
-            if (!CustomAppend(block_info)) {
-                FatalErrorf("%s: Failed to write block %s to index database",
-                           __func__, pindex->GetBlockHash().ToString());
-                return;
-            }
+            if (!ProcessBlock(pindex)) return; // error logged internally
 
             auto current_time{std::chrono::steady_clock::now()};
             if (last_log_time + SYNC_LOG_INTERVAL < current_time) {
@@ -337,17 +359,14 @@ void BaseIndex::BlockConnected(ChainstateRole role, const std::shared_ptr<const
             return;
         }
     }
-    interfaces::BlockInfo block_info = kernel::MakeBlockInfo(pindex, block.get());
-    if (CustomAppend(block_info)) {
+
+    // Dispatch block to child class; errors are logged internally and abort the node.
+    if (ProcessBlock(pindex, block.get())) {
         // Setting the best block index is intentionally the last step of this
         // function, so BlockUntilSyncedToCurrentChain callers waiting for the
         // best block index to be updated can rely on the block being fully
         // processed, and the index object being safe to delete.
         SetBestBlockIndex(pindex);
-    } else {
-        FatalErrorf("%s: Failed to write block %s to index",
-                   __func__, pindex->GetBlockHash().ToString());
-        return;
     }
 }
 
diff --git a/src/index/base.h b/src/index/base.h
index 841bfcb00e..4131b06cad 100644
--- a/src/index/base.h
+++ b/src/index/base.h
@@ -93,6 +93,8 @@ private:
     /// Loop over disconnected blocks and call CustomRemove.
     bool Rewind(const CBlockIndex* current_tip, const CBlockIndex* new_tip);
 
+    bool ProcessBlock(const CBlockIndex* pindex, const CBlock* block_data = nullptr);
+
     virtual bool AllowPrune() const = 0;
 
     template <typename... Args>
diff --git a/src/index/blockfilterindex.cpp b/src/index/blockfilterindex.cpp
index de55170daa..de43e8e271 100644
--- a/src/index/blockfilterindex.cpp
+++ b/src/index/blockfilterindex.cpp
@@ -13,7 +13,6 @@
 #include <node/blockstorage.h>
 #include <undo.h>
 #include <util/fs_helpers.h>
-#include <validation.h>
 
 /* The index database stores three items for each block: the disk location of the encoded filter,
  * its dSHA256 hash, and the header. Those belonging to blocks on the active chain are indexed by
@@ -112,6 +111,13 @@ BlockFilterIndex::BlockFilterIndex(std::unique_ptr<interfaces::Chain> chain, Blo
     m_filter_fileseq = std::make_unique<FlatFileSeq>(std::move(path), "fltr", FLTR_FILE_CHUNK_SIZE);
 }
 
+interfaces::Chain::NotifyOptions BlockFilterIndex::CustomOptions()
+{
+    interfaces::Chain::NotifyOptions options;
+    options.connect_undo_data = true;
+    return options;
+}
+
 bool BlockFilterIndex::CustomInit(const std::optional<interfaces::BlockRef>& block)
 {
     if (!m_db->Read(DB_FILTER_POS, m_next_filter_pos)) {
@@ -250,19 +256,7 @@ std::optional<uint256> BlockFilterIndex::ReadFilterHeader(int height, const uint
 
 bool BlockFilterIndex::CustomAppend(const interfaces::BlockInfo& block)
 {
-    CBlockUndo block_undo;
-
-    if (block.height > 0) {
-        // pindex variable gives indexing code access to node internals. It
-        // will be removed in upcoming commit
-        const CBlockIndex* pindex = WITH_LOCK(cs_main, return m_chainstate->m_blockman.LookupBlockIndex(block.hash));
-        if (!m_chainstate->m_blockman.ReadBlockUndo(block_undo, *pindex)) {
-            return false;
-        }
-    }
-
-    BlockFilter filter(m_filter_type, *Assert(block.data), block_undo);
-
+    BlockFilter filter(m_filter_type, *Assert(block.data), *Assert(block.undo_data));
     const uint256& header = filter.ComputeHeader(m_last_header);
     bool res = Write(filter, block.height, header);
     if (res) m_last_header = header; // update last header
diff --git a/src/index/blockfilterindex.h b/src/index/blockfilterindex.h
index 13543b961c..983cf32206 100644
--- a/src/index/blockfilterindex.h
+++ b/src/index/blockfilterindex.h
@@ -52,6 +52,8 @@ private:
     std::optional<uint256> ReadFilterHeader(int height, const uint256& expected_block_hash);
 
 protected:
+    interfaces::Chain::NotifyOptions CustomOptions() override;
+
     bool CustomInit(const std::optional<interfaces::BlockRef>& block) override;
 
     bool CustomCommit(CDBBatch& batch) override;
diff --git a/src/index/coinstatsindex.cpp b/src/index/coinstatsindex.cpp
index 28e7d66e8f..ef2af8a567 100644
--- a/src/index/coinstatsindex.cpp
+++ b/src/index/coinstatsindex.cpp
@@ -114,19 +114,11 @@ CoinStatsIndex::CoinStatsIndex(std::unique_ptr<interfaces::Chain> chain, size_t
 
 bool CoinStatsIndex::CustomAppend(const interfaces::BlockInfo& block)
 {
-    CBlockUndo block_undo;
     const CAmount block_subsidy{GetBlockSubsidy(block.height, Params().GetConsensus())};
     m_total_subsidy += block_subsidy;
 
     // Ignore genesis block
     if (block.height > 0) {
-        // pindex variable gives indexing code access to node internals. It
-        // will be removed in upcoming commit
-        const CBlockIndex* pindex = WITH_LOCK(cs_main, return m_chainstate->m_blockman.LookupBlockIndex(block.hash));
-        if (!m_chainstate->m_blockman.ReadBlockUndo(block_undo, *pindex)) {
-            return false;
-        }
-
         std::pair<uint256, DBVal> read_out;
         if (!m_db->Read(DBHeightKey(block.height - 1), read_out)) {
             return false;
@@ -183,7 +175,7 @@ bool CoinStatsIndex::CustomAppend(const interfaces::BlockInfo& block)
 
             // The coinbase tx has no undo data since no former output is spent
             if (!tx->IsCoinBase()) {
-                const auto& tx_undo{block_undo.vtxundo.at(i - 1)};
+                const auto& tx_undo{Assert(block.undo_data)->vtxundo.at(i - 1)};
 
                 for (size_t j = 0; j < tx_undo.vprevout.size(); ++j) {
                     Coin coin{tx_undo.vprevout[j]};
@@ -383,6 +375,7 @@ bool CoinStatsIndex::CustomCommit(CDBBatch& batch)
 interfaces::Chain::NotifyOptions CoinStatsIndex::CustomOptions()
 {
     interfaces::Chain::NotifyOptions options;
+    options.connect_undo_data = true;
     options.disconnect_data = true;
     options.disconnect_undo_data = true;
     return options;
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index f98eeeed8b..f6e831624d 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -330,6 +330,8 @@ public:
     //! Options specifying which chain notifications are required.
     struct NotifyOptions
     {
+        //! Include undo data with block connected notifications.
+        bool connect_undo_data = false;
         //! Include block data with block disconnected notifications.
         bool disconnect_data = false;
         //! Include undo data with block disconnected notifications.