diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 1e3d7131a..1d6b60ca0 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -1,198 +1,199 @@
 // Copyright (c) 2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <interfaces/chain.h>
 
 #include <chain.h>
 #include <chainparams.h>
 #include <primitives/block.h>
 #include <primitives/blockhash.h>
 #include <sync.h>
 #include <threadsafety.h>
+#include <txmempool.h>
 #include <util/system.h>
 #include <validation.h>
 
 #include <memory>
 #include <utility>
 
 namespace interfaces {
 namespace {
 
     class LockImpl : public Chain::Lock {
         Optional<int> getHeight() override {
             int height = ::ChainActive().Height();
             if (height >= 0) {
                 return height;
             }
             return nullopt;
         }
         Optional<int> getBlockHeight(const BlockHash &hash) override {
             CBlockIndex *block = LookupBlockIndex(hash);
             if (block && ::ChainActive().Contains(block)) {
                 return block->nHeight;
             }
             return nullopt;
         }
         int getBlockDepth(const BlockHash &hash) override {
             const Optional<int> tip_height = getHeight();
             const Optional<int> height = getBlockHeight(hash);
             return tip_height && height ? *tip_height - *height + 1 : 0;
         }
         BlockHash getBlockHash(int height) override {
             CBlockIndex *block = ::ChainActive()[height];
             assert(block != nullptr);
             return block->GetBlockHash();
         }
         int64_t getBlockTime(int height) override {
             CBlockIndex *block = ::ChainActive()[height];
             assert(block != nullptr);
             return block->GetBlockTime();
         }
         int64_t getBlockMedianTimePast(int height) override {
             CBlockIndex *block = ::ChainActive()[height];
             assert(block != nullptr);
             return block->GetMedianTimePast();
         }
         bool haveBlockOnDisk(int height) override {
             CBlockIndex *block = ::ChainActive()[height];
             return block && (block->nStatus.hasData() != 0) && block->nTx > 0;
         }
         Optional<int> findFirstBlockWithTime(int64_t time,
                                              BlockHash *hash) override {
             CBlockIndex *block = ::ChainActive().FindEarliestAtLeast(time);
             if (block) {
                 if (hash) {
                     *hash = block->GetBlockHash();
                 }
                 return block->nHeight;
             }
             return nullopt;
         }
         Optional<int> findFirstBlockWithTimeAndHeight(int64_t time,
                                                       int height) override {
             // TODO: Could update CChain::FindEarliestAtLeast() to take a height
             // parameter and use it with std::lower_bound() to make this
             // implementation more efficient and allow combining
             // findFirstBlockWithTime and findFirstBlockWithTimeAndHeight into
             // one method.
             for (CBlockIndex *block = ::ChainActive()[height]; block;
                  block = ::ChainActive().Next(block)) {
                 if (block->GetBlockTime() >= time) {
                     return block->nHeight;
                 }
             }
             return nullopt;
         }
         Optional<int> findPruned(int start_height,
                                  Optional<int> stop_height) override {
             if (::fPruneMode) {
                 CBlockIndex *block = stop_height ? ::ChainActive()[*stop_height]
                                                  : ::ChainActive().Tip();
                 while (block && block->nHeight >= start_height) {
                     if (block->nStatus.hasData() == 0) {
                         return block->nHeight;
                     }
                     block = block->pprev;
                 }
             }
             return nullopt;
         }
         Optional<int> findFork(const BlockHash &hash,
                                Optional<int> *height) override {
             const CBlockIndex *block = LookupBlockIndex(hash);
             const CBlockIndex *fork =
                 block ? ::ChainActive().FindFork(block) : nullptr;
             if (height) {
                 if (block) {
                     *height = block->nHeight;
                 } else {
                     height->reset();
                 }
             }
             if (fork) {
                 return fork->nHeight;
             }
             return nullopt;
         }
         bool isPotentialTip(const BlockHash &hash) override {
             if (::ChainActive().Tip()->GetBlockHash() == hash) {
                 return true;
             }
             CBlockIndex *block = LookupBlockIndex(hash);
             return block && block->GetAncestor(::ChainActive().Height()) ==
                                 ::ChainActive().Tip();
         }
         CBlockLocator getLocator() override {
             return ::ChainActive().GetLocator();
         }
         Optional<int> findLocatorFork(const CBlockLocator &locator) override {
             LockAnnotation lock(::cs_main);
             if (CBlockIndex *fork =
                     FindForkInGlobalIndex(::ChainActive(), locator)) {
                 return fork->nHeight;
             }
             return nullopt;
         }
         bool contextualCheckTransactionForCurrentBlock(
             const Consensus::Params &params, const CTransaction &tx,
             CValidationState &state) override {
             LockAnnotation lock(::cs_main);
             return ContextualCheckTransactionForCurrentBlock(params, tx, state);
         }
     };
 
     class LockingStateImpl : public LockImpl,
                              public UniqueLock<CCriticalSection> {
         using UniqueLock::UniqueLock;
     };
 
     class ChainImpl : public Chain {
     public:
         std::unique_ptr<Chain::Lock> lock(bool try_lock) override {
             auto result = std::make_unique<LockingStateImpl>(
                 ::cs_main, "cs_main", __FILE__, __LINE__, try_lock);
             if (try_lock && result && !*result) {
                 return {};
             }
             return result;
         }
         std::unique_ptr<Chain::Lock> assumeLocked() override {
             return std::make_unique<LockImpl>();
         }
         bool findBlock(const BlockHash &hash, CBlock *block, int64_t *time,
                        int64_t *time_max) override {
             CBlockIndex *index;
             {
                 LOCK(cs_main);
                 index = LookupBlockIndex(hash);
                 if (!index) {
                     return false;
                 }
                 if (time) {
                     *time = index->GetBlockTime();
                 }
                 if (time_max) {
                     *time_max = index->GetBlockTimeMax();
                 }
             }
             if (block &&
                 !ReadBlockFromDisk(*block, index, Params().GetConsensus())) {
                 block->SetNull();
             }
             return true;
         }
         double guessVerificationProgress(const BlockHash &block_hash) override {
             LOCK(cs_main);
             return GuessVerificationProgress(Params().TxData(),
                                              LookupBlockIndex(block_hash));
         }
     };
 
 } // namespace
 
 std::unique_ptr<Chain> MakeChain() {
     return std::make_unique<ChainImpl>();
 }
 
 } // namespace interfaces