diff --git a/src/gridcoin/staking/kernel.cpp b/src/gridcoin/staking/kernel.cpp
index 1eb8e195ab..47e436643b 100644
--- a/src/gridcoin/staking/kernel.cpp
+++ b/src/gridcoin/staking/kernel.cpp
@@ -12,6 +12,8 @@
 #include "streams.h"
 #include "util.h"
 
+#include <node/blockstorage.h>
+
 using namespace std;
 using namespace GRC;
 
@@ -385,12 +387,28 @@ bool GRC::ReadStakedInput(
     CTxDB& txdb,
     const uint256 prevout_hash,
     CBlockHeader& out_header,
-    CTransaction& out_txprev)
+    CTransaction& out_txprev,
+    CBlockIndex* pindexPrev)
 {
     CTxIndex tx_index;
 
     // Get transaction index for the previous transaction
     if (!txdb.ReadTxIndex(prevout_hash, tx_index)) {
+        if (pindexPrev != nullptr) {
+            for (CBlockIndex* pindex = pindexPrev; pindex->pprev != nullptr; pindex = pindex->pprev) {
+                CBlock block;
+                ReadBlockFromDisk(block, pindex, Params().GetConsensus());
+
+                for (const auto& tx : block.vtx) {
+                    if (tx.GetHash() == prevout_hash) {
+                        error("Found tx %s in block %s", tx.GetHash().ToString(), pindex->GetBlockHash().ToString());
+                        out_txprev = tx;
+                        out_header = pindex->GetBlockHeader();
+                        return true;
+                    }
+                }
+            }
+        }
         // Previous transaction not in main chain, may occur during initial download
         return error("%s: tx index not found for input tx %s", __func__, prevout_hash.GetHex());
     }
@@ -429,7 +447,7 @@ bool GRC::CalculateLegacyV3HashProof(
     CTransaction input_tx;
     CBlockHeader input_block;
 
-    if (!ReadStakedInput(txdb, prevout.hash, input_block, input_tx)) {
+    if (!ReadStakedInput(txdb, prevout.hash, input_block, input_tx, nullptr)) {
         return coinstake.DoS(1, error("Read staked input failed."));
     }
 
@@ -584,7 +602,7 @@ bool GRC::CheckProofOfStakeV8(
     CBlockHeader header;
     CTransaction txPrev;
 
-    if (!ReadStakedInput(txdb, prevout.hash, header, txPrev))
+    if (!ReadStakedInput(txdb, prevout.hash, header, txPrev, pindexPrev))
         return tx.DoS(1, error("%s: read staked input failed", __func__));
 
     if (!VerifySignature(txPrev, tx, 0, 0))
diff --git a/src/gridcoin/staking/kernel.h b/src/gridcoin/staking/kernel.h
index 237ea7b4b7..380355daad 100644
--- a/src/gridcoin/staking/kernel.h
+++ b/src/gridcoin/staking/kernel.h
@@ -57,7 +57,8 @@ bool ReadStakedInput(
     CTxDB& txdb,
     const uint256 prevout_hash,
     CBlockHeader& out_header,
-    CTransaction& out_txprev);
+    CTransaction& out_txprev,
+    CBlockIndex* pindexPrev = nullptr);
 
 //!
 //! \brief Calculate the provided block's proof hash with the version 3 staking
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index f491b723a8..502686fa9f 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -15,7 +15,10 @@
 
 bool WriteBlockToDisk(const CBlock& block, unsigned int& nFileRet, unsigned int& nBlockPosRet,
                       const CMessageHeader::MessageStartChars& messageStart)
+        EXCLUSIVE_LOCKS_REQUIRED(cs_main)
 {
+    AssertLockHeld(cs_main);
+
     // Open history file to append
     CAutoFile fileout(AppendBlockFile(nFileRet), SER_DISK, CLIENT_VERSION);
     if (fileout.IsNull())
diff --git a/src/validation.cpp b/src/validation.cpp
index 775dc60181..ee78d93bf5 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1752,7 +1752,10 @@ bool AddToBlockIndex(CBlock& block, unsigned int nFile, unsigned int nBlockPos,
 }
 
 bool CheckBlock(const CBlock& block, int height1, bool fCheckPOW, bool fCheckMerkleRoot, bool fCheckSig, bool fLoadingIndex)
+        EXCLUSIVE_LOCKS_REQUIRED(cs_main)
 {
+    AssertLockHeld(cs_main);
+
     // Allow the genesis block to pass.
     if(block.hashPrevBlock.IsNull() &&
        block.GetHash(true) == (fTestNet ? hashGenesisBlockTestNet : hashGenesisBlock))