diff --git a/src/validation.cpp b/src/validation.cpp
index b7af84127..74e967184 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1556,6 +1556,43 @@ void static FlushBlockFile(bool fFinalize = false)
 
 static bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigned int nAddSize);
 
+static bool WriteUndoDataForBlock(const CBlockUndo& blockundo, CValidationState& state, CBlockIndex* pindex, const CChainParams& chainparams)
+{
+    // Write undo information to disk
+    if (pindex->GetUndoPos().IsNull()) {
+        CDiskBlockPos _pos;
+        if (!FindUndoPos(state, pindex->nFile, _pos, ::GetSerializeSize(blockundo, SER_DISK, CLIENT_VERSION) + 40))
+            return error("ConnectBlock(): FindUndoPos failed");
+        if (!UndoWriteToDisk(blockundo, _pos, pindex->pprev->GetBlockHash(), chainparams.MessageStart()))
+            return AbortNode(state, "Failed to write undo data");
+
+        // update nUndoPos in block index
+        pindex->nUndoPos = _pos.nPos;
+        pindex->nStatus |= BLOCK_HAVE_UNDO;
+        setDirtyBlockIndex.insert(pindex);
+    }
+
+    return true;
+}
+
+static bool WriteTxIndexDataForBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex)
+{
+    CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
+    std::vector<std::pair<uint256, CDiskTxPos> > vPos;
+    vPos.reserve(block.vtx.size());
+    for (const CTransactionRef& tx : block.vtx)
+    {
+        vPos.push_back(std::make_pair(tx->GetHash(), pos));
+        pos.nTxOffset += ::GetSerializeSize(*tx, SER_DISK, CLIENT_VERSION);
+    }
+
+    if (fTxIndex)
+        if (!pblocktree->WriteTxIndex(vPos))
+            return AbortNode(state, "Failed to write transaction index");
+
+    return true;
+}
+
 static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
 
 void ThreadScriptCheck() {
@@ -1783,9 +1820,6 @@ static bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockInd
     CAmount nFees = 0;
     int nInputs = 0;
     int64_t nSigOpsCost = 0;
-    CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
-    std::vector<std::pair<uint256, CDiskTxPos> > vPos;
-    vPos.reserve(block.vtx.size());
     blockundo.vtxundo.reserve(block.vtx.size() - 1);
     std::vector<PrecomputedTransactionData> txdata;
     txdata.reserve(block.vtx.size()); // Required so that pointers to individual PrecomputedTransactionData don't get invalidated
@@ -1846,9 +1880,6 @@ static bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockInd
             blockundo.vtxundo.push_back(CTxUndo());
         }
         UpdateCoins(tx, view, i == 0 ? undoDummy : blockundo.vtxundo.back(), pindex->nHeight);
-
-        vPos.push_back(std::make_pair(tx.GetHash(), pos));
-        pos.nTxOffset += ::GetSerializeSize(tx, SER_DISK, CLIENT_VERSION);
     }
     int64_t nTime3 = GetTimeMicros(); nTimeConnect += nTime3 - nTime2;
     LogPrint(BCLog::BENCH, "      - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) [%.2fs (%.2fms/blk)]\n", (unsigned)block.vtx.size(), MILLI * (nTime3 - nTime2), MILLI * (nTime3 - nTime2) / block.vtx.size(), nInputs <= 1 ? 0 : MILLI * (nTime3 - nTime2) / (nInputs-1), nTimeConnect * MICRO, nTimeConnect * MILLI / nBlocksTotal);
@@ -1868,28 +1899,16 @@ static bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockInd
     if (fJustCheck)
         return true;
 
-    // Write undo information to disk
-    if (pindex->GetUndoPos().IsNull() || !pindex->IsValid(BLOCK_VALID_SCRIPTS))
-    {
-        if (pindex->GetUndoPos().IsNull()) {
-            CDiskBlockPos _pos;
-            if (!FindUndoPos(state, pindex->nFile, _pos, ::GetSerializeSize(blockundo, SER_DISK, CLIENT_VERSION) + 40))
-                return error("ConnectBlock(): FindUndoPos failed");
-            if (!UndoWriteToDisk(blockundo, _pos, pindex->pprev->GetBlockHash(), chainparams.MessageStart()))
-                return AbortNode(state, "Failed to write undo data");
-
-            // update nUndoPos in block index
-            pindex->nUndoPos = _pos.nPos;
-            pindex->nStatus |= BLOCK_HAVE_UNDO;
-        }
+    if (!WriteUndoDataForBlock(blockundo, state, pindex, chainparams))
+        return false;
 
+    if (!pindex->IsValid(BLOCK_VALID_SCRIPTS)) {
         pindex->RaiseValidity(BLOCK_VALID_SCRIPTS);
         setDirtyBlockIndex.insert(pindex);
     }
 
-    if (fTxIndex)
-        if (!pblocktree->WriteTxIndex(vPos))
-            return AbortNode(state, "Failed to write transaction index");
+    if (!WriteTxIndexDataForBlock(block, state, pindex))
+        return false;
 
     assert(pindex->phashBlock);
     // add this block to the view's block chain