diff --git a/contrib/devtools/test_deterministic_coverage.sh b/contrib/devtools/test_deterministic_coverage.sh
index 8501c72f04a..23c260b529f 100755
--- a/contrib/devtools/test_deterministic_coverage.sh
+++ b/contrib/devtools/test_deterministic_coverage.sh
@@ -17,21 +17,21 @@ NON_DETERMINISTIC_TESTS=(
     "blockfilter_index_tests/blockfilter_index_initial_sync"  # src/checkqueue.h: In CCheckQueue::Loop(): while (queue.empty()) { ... }
     "coinselector_tests/knapsack_solver_test"                 # coinselector_tests.cpp: if (equal_sets(setCoinsRet, setCoinsRet2))
     "fs_tests/fsbridge_fstream"                               # deterministic test failure?
-    "miner_tests/CreateNewBlock_validity"                     # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
+    "miner_tests/CreateNewBlock_validity"                     # validation.cpp: if (signals.CallbacksPending() > 10)
     "scheduler_tests/manythreads"                             # scheduler.cpp: CScheduler::serviceQueue()
     "scheduler_tests/singlethreadedscheduler_ordered"         # scheduler.cpp: CScheduler::serviceQueue()
-    "txvalidationcache_tests/checkinputs_test"                # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "txvalidationcache_tests/tx_mempool_block_doublespend"    # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "txindex_tests/txindex_initial_sync"                      # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "txvalidation_tests/tx_mempool_reject_coinbase"           # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "validation_block_tests/processnewblock_signals_ordering" # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "wallet_tests/coin_mark_dirty_immature_credit"            # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "wallet_tests/dummy_input_size_test"                      # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "wallet_tests/importmulti_rescan"                         # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "wallet_tests/importwallet_rescan"                        # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "wallet_tests/ListCoins"                                  # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "wallet_tests/scan_for_wallet_transactions"               # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
-    "wallet_tests/wallet_disableprivkeys"                     # validation.cpp: if (GetMainSignals().CallbacksPending() > 10)
+    "txvalidationcache_tests/checkinputs_test"                # validation.cpp: if (signals.CallbacksPending() > 10)
+    "txvalidationcache_tests/tx_mempool_block_doublespend"    # validation.cpp: if (signals.CallbacksPending() > 10)
+    "txindex_tests/txindex_initial_sync"                      # validation.cpp: if (signals.CallbacksPending() > 10)
+    "txvalidation_tests/tx_mempool_reject_coinbase"           # validation.cpp: if (signals.CallbacksPending() > 10)
+    "validation_block_tests/processnewblock_signals_ordering" # validation.cpp: if (signals.CallbacksPending() > 10)
+    "wallet_tests/coin_mark_dirty_immature_credit"            # validation.cpp: if (signals.CallbacksPending() > 10)
+    "wallet_tests/dummy_input_size_test"                      # validation.cpp: if (signals.CallbacksPending() > 10)
+    "wallet_tests/importmulti_rescan"                         # validation.cpp: if (signals.CallbacksPending() > 10)
+    "wallet_tests/importwallet_rescan"                        # validation.cpp: if (signals.CallbacksPending() > 10)
+    "wallet_tests/ListCoins"                                  # validation.cpp: if (signals.CallbacksPending() > 10)
+    "wallet_tests/scan_for_wallet_transactions"               # validation.cpp: if (signals.CallbacksPending() > 10)
+    "wallet_tests/wallet_disableprivkeys"                     # validation.cpp: if (signals.CallbacksPending() > 10)
 )
 
 TEST_BITCOIN_BINARY="src/test/test_bitcoin"
diff --git a/src/Makefile.am b/src/Makefile.am
index d797ac880b9..1f55bfbafda 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -323,6 +323,7 @@ BITCOIN_CORE_H = \
   util/spanparsing.h \
   util/string.h \
   util/syserror.h \
+  util/task_runner.h \
   util/thread.h \
   util/threadinterrupt.h \
   util/threadnames.h \
@@ -966,7 +967,6 @@ libbitcoinkernel_la_SOURCES = \
   pubkey.cpp \
   random.cpp \
   randomenv.cpp \
-  scheduler.cpp \
   script/interpreter.cpp \
   script/script.cpp \
   script/script_error.cpp \
@@ -983,7 +983,6 @@ libbitcoinkernel_la_SOURCES = \
   util/batchpriority.cpp \
   util/chaintype.cpp \
   util/check.cpp \
-  util/exception.cpp \
   util/fs.cpp \
   util/fs_helpers.cpp \
   util/hasher.cpp \
@@ -994,7 +993,6 @@ libbitcoinkernel_la_SOURCES = \
   util/strencodings.cpp \
   util/string.cpp \
   util/syserror.cpp \
-  util/thread.cpp \
   util/threadnames.cpp \
   util/time.cpp \
   util/tokenpipe.cpp \
diff --git a/src/bench/wallet_balance.cpp b/src/bench/wallet_balance.cpp
index bf2195293ef..7a10b167a67 100644
--- a/src/bench/wallet_balance.cpp
+++ b/src/bench/wallet_balance.cpp
@@ -39,7 +39,8 @@ static void WalletBalance(benchmark::Bench& bench, const bool set_dirty, const b
         generatetoaddress(test_setup->m_node, address_mine.value_or(ADDRESS_WATCHONLY));
         generatetoaddress(test_setup->m_node, ADDRESS_WATCHONLY);
     }
-    SyncWithValidationInterfaceQueue();
+    // Calls SyncWithValidationInterfaceQueue
+    wallet.chain().waitForNotificationsIfTipChanged(uint256::ZERO);
 
     auto bal = GetBalance(wallet); // Cache
 
diff --git a/src/bitcoin-chainstate.cpp b/src/bitcoin-chainstate.cpp
index c1a71ed7498..3eb64aa344b 100644
--- a/src/bitcoin-chainstate.cpp
+++ b/src/bitcoin-chainstate.cpp
@@ -23,11 +23,10 @@
 #include <node/caches.h>
 #include <node/chainstate.h>
 #include <random.h>
-#include <scheduler.h>
 #include <script/sigcache.h>
 #include <util/chaintype.h>
 #include <util/fs.h>
-#include <util/thread.h>
+#include <util/task_runner.h>
 #include <validation.h>
 #include <validationinterface.h>
 
@@ -68,16 +67,7 @@ int main(int argc, char* argv[])
     Assert(InitSignatureCache(validation_cache_sizes.signature_cache_bytes));
     Assert(InitScriptExecutionCache(validation_cache_sizes.script_execution_cache_bytes));
 
-
-    // SETUP: Scheduling and Background Signals
-    CScheduler scheduler{};
-    // Start the lightweight task scheduler thread
-    scheduler.m_service_thread = std::thread(util::TraceThread, "scheduler", [&] { scheduler.serviceQueue(); });
-
-    // Gather some entropy once per minute.
-    scheduler.scheduleEvery(RandAddPeriodic, std::chrono::minutes{1});
-
-    GetMainSignals().RegisterBackgroundSignalScheduler(scheduler);
+    ValidationSignals validation_signals{std::make_unique<util::ImmediateTaskRunner>()};
 
     class KernelNotifications : public kernel::Notifications
     {
@@ -118,6 +108,7 @@ int main(int argc, char* argv[])
         .chainparams = *chainparams,
         .datadir = abs_datadir,
         .notifications = *notifications,
+        .signals = &validation_signals,
     };
     const node::BlockManager::Options blockman_opts{
         .chainparams = chainman_opts.chainparams,
@@ -235,9 +226,9 @@ int main(int argc, char* argv[])
 
         bool new_block;
         auto sc = std::make_shared<submitblock_StateCatcher>(block.GetHash());
-        RegisterSharedValidationInterface(sc);
+        validation_signals.RegisterSharedValidationInterface(sc);
         bool accepted = chainman.ProcessNewBlock(blockptr, /*force_processing=*/true, /*min_pow_checked=*/true, /*new_block=*/&new_block);
-        UnregisterSharedValidationInterface(sc);
+        validation_signals.UnregisterSharedValidationInterface(sc);
         if (!new_block && accepted) {
             std::cerr << "duplicate" << std::endl;
             break;
@@ -287,10 +278,9 @@ int main(int argc, char* argv[])
 epilogue:
     // Without this precise shutdown sequence, there will be a lot of nullptr
     // dereferencing and UB.
-    scheduler.stop();
     if (chainman.m_thread_load.joinable()) chainman.m_thread_load.join();
 
-    GetMainSignals().FlushBackgroundCallbacks();
+    validation_signals.FlushBackgroundCallbacks();
     {
         LOCK(cs_main);
         for (Chainstate* chainstate : chainman.GetAll()) {
@@ -300,5 +290,4 @@ epilogue:
             }
         }
     }
-    GetMainSignals().UnregisterBackgroundSignalScheduler();
 }
diff --git a/src/index/base.cpp b/src/index/base.cpp
index bcfe7215bea..2287437f8f0 100644
--- a/src/index/base.cpp
+++ b/src/index/base.cpp
@@ -89,7 +89,7 @@ bool BaseIndex::Init()
         return &m_chain->context()->chainman->GetChainstateForIndexing());
     // Register to validation interface before setting the 'm_synced' flag, so that
     // callbacks are not missed once m_synced is true.
-    RegisterValidationInterface(this);
+    m_chain->context()->validation_signals->RegisterValidationInterface(this);
 
     CBlockLocator locator;
     if (!GetDB().ReadBestBlock(locator)) {
@@ -380,7 +380,7 @@ bool BaseIndex::BlockUntilSyncedToCurrentChain() const
     }
 
     LogPrintf("%s: %s is catching up on block notifications\n", __func__, GetName());
-    SyncWithValidationInterfaceQueue();
+    m_chain->context()->validation_signals->SyncWithValidationInterfaceQueue();
     return true;
 }
 
@@ -399,7 +399,9 @@ bool BaseIndex::StartBackgroundSync()
 
 void BaseIndex::Stop()
 {
-    UnregisterValidationInterface(this);
+    if (m_chain->context()->validation_signals) {
+        m_chain->context()->validation_signals->UnregisterValidationInterface(this);
+    }
 
     if (m_thread_sync.joinable()) {
         m_thread_sync.join();
diff --git a/src/init.cpp b/src/init.cpp
index 988daefeec8..9ea7b881cb0 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -291,7 +291,7 @@ void Shutdown(NodeContext& node)
 
     // Because these depend on each-other, we make sure that neither can be
     // using the other before destroying them.
-    if (node.peerman) UnregisterValidationInterface(node.peerman.get());
+    if (node.peerman && node.validation_signals) node.validation_signals->UnregisterValidationInterface(node.peerman.get());
     if (node.connman) node.connman->Stop();
 
     StopTorControl();
@@ -317,7 +317,9 @@ void Shutdown(NodeContext& node)
     // fee estimator from validation interface.
     if (node.fee_estimator) {
         node.fee_estimator->Flush();
-        UnregisterValidationInterface(node.fee_estimator.get());
+        if (node.validation_signals) {
+            node.validation_signals->UnregisterValidationInterface(node.fee_estimator.get());
+        }
     }
 
     // FlushStateToDisk generates a ChainStateFlushed callback, which we should avoid missing
@@ -332,7 +334,7 @@ void Shutdown(NodeContext& node)
 
     // After there are no more peers/RPC left to give us new data which may generate
     // CValidationInterface callbacks, flush them...
-    GetMainSignals().FlushBackgroundCallbacks();
+    if (node.validation_signals) node.validation_signals->FlushBackgroundCallbacks();
 
     // Stop and delete all indexes only after flushing background callbacks.
     if (g_txindex) {
@@ -367,17 +369,19 @@ void Shutdown(NodeContext& node)
 
 #if ENABLE_ZMQ
     if (g_zmq_notification_interface) {
-        UnregisterValidationInterface(g_zmq_notification_interface.get());
+        if (node.validation_signals) node.validation_signals->UnregisterValidationInterface(g_zmq_notification_interface.get());
         g_zmq_notification_interface.reset();
     }
 #endif
 
     node.chain_clients.clear();
-    UnregisterAllValidationInterfaces();
-    GetMainSignals().UnregisterBackgroundSignalScheduler();
+    if (node.validation_signals) {
+        node.validation_signals->UnregisterAllValidationInterfaces();
+    }
     node.mempool.reset();
     node.fee_estimator.reset();
     node.chainman.reset();
+    node.validation_signals.reset();
     node.scheduler.reset();
     node.kernel.reset();
 
@@ -1138,17 +1142,18 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
     assert(!node.scheduler);
     node.scheduler = std::make_unique<CScheduler>();
+    auto& scheduler = *node.scheduler;
 
     // Start the lightweight task scheduler thread
-    node.scheduler->m_service_thread = std::thread(util::TraceThread, "scheduler", [&] { node.scheduler->serviceQueue(); });
+    scheduler.m_service_thread = std::thread(util::TraceThread, "scheduler", [&] { scheduler.serviceQueue(); });
 
     // Gather some entropy once per minute.
-    node.scheduler->scheduleEvery([]{
+    scheduler.scheduleEvery([]{
         RandAddPeriodic();
     }, std::chrono::minutes{1});
 
     // Check disk space every 5 minutes to avoid db corruption.
-    node.scheduler->scheduleEvery([&args, &node]{
+    scheduler.scheduleEvery([&args, &node]{
         constexpr uint64_t min_disk_space = 50 << 20; // 50 MB
         if (!CheckDiskSpace(args.GetBlocksDirPath(), min_disk_space)) {
             LogPrintf("Shutting down due to lack of disk space!\n");
@@ -1158,7 +1163,9 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         }
     }, std::chrono::minutes{5});
 
-    GetMainSignals().RegisterBackgroundSignalScheduler(*node.scheduler);
+    assert(!node.validation_signals);
+    node.validation_signals = std::make_unique<ValidationSignals>(std::make_unique<SerialTaskRunner>(scheduler));
+    auto& validation_signals = *node.validation_signals;
 
     // Create client interfaces for wallets that are supposed to be loaded
     // according to -wallet and -disablewallet options. This only constructs
@@ -1263,8 +1270,8 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
         // Flush estimates to disk periodically
         CBlockPolicyEstimator* fee_estimator = node.fee_estimator.get();
-        node.scheduler->scheduleEvery([fee_estimator] { fee_estimator->FlushFeeEstimates(); }, FEE_FLUSH_INTERVAL);
-        RegisterValidationInterface(fee_estimator);
+        scheduler.scheduleEvery([fee_estimator] { fee_estimator->FlushFeeEstimates(); }, FEE_FLUSH_INTERVAL);
+        validation_signals.RegisterValidationInterface(fee_estimator);
     }
 
     // Check port numbers
@@ -1435,7 +1442,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         });
 
     if (g_zmq_notification_interface) {
-        RegisterValidationInterface(g_zmq_notification_interface.get());
+        validation_signals.RegisterValidationInterface(g_zmq_notification_interface.get());
     }
 #endif
 
@@ -1449,6 +1456,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         .chainparams = chainparams,
         .datadir = args.GetDataDirNet(),
         .notifications = *node.notifications,
+        .signals = &validation_signals,
     };
     Assert(ApplyArgsManOptions(args, chainman_opts)); // no error can happen, already checked in AppInitParameterInteraction
 
@@ -1478,6 +1486,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
     CTxMemPool::Options mempool_opts{
         .check_ratio = chainparams.DefaultConsistencyChecks() ? 1 : 0,
+        .signals = &validation_signals,
     };
     auto result{ApplyArgsManOptions(args, chainparams, mempool_opts)};
     if (!result) {
@@ -1505,7 +1514,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
             // Drain the validation interface queue to ensure that the old indexes
             // don't have any pending work.
-            SyncWithValidationInterfaceQueue();
+            Assert(node.validation_signals)->SyncWithValidationInterfaceQueue();
 
             for (auto* index : node.indexes) {
                 index->Interrupt();
@@ -1594,7 +1603,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     node.peerman = PeerManager::make(*node.connman, *node.addrman,
                                      node.banman.get(), chainman,
                                      *node.mempool, peerman_opts);
-    RegisterValidationInterface(node.peerman.get());
+    validation_signals.RegisterValidationInterface(node.peerman.get());
 
     // ********************************************************* Step 8: start indexers
 
@@ -1900,7 +1909,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
     connOptions.m_i2p_accept_incoming = args.GetBoolArg("-i2pacceptincoming", DEFAULT_I2P_ACCEPT_INCOMING);
 
-    if (!node.connman->Start(*node.scheduler, connOptions)) {
+    if (!node.connman->Start(scheduler, connOptions)) {
         return false;
     }
 
@@ -1920,15 +1929,15 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     uiInterface.InitMessage(_("Done loading").translated);
 
     for (const auto& client : node.chain_clients) {
-        client->start(*node.scheduler);
+        client->start(scheduler);
     }
 
     BanMan* banman = node.banman.get();
-    node.scheduler->scheduleEvery([banman]{
+    scheduler.scheduleEvery([banman]{
         banman->DumpBanlist();
     }, DUMP_BANS_INTERVAL);
 
-    if (node.peerman) node.peerman->StartScheduledTasks(*node.scheduler);
+    if (node.peerman) node.peerman->StartScheduledTasks(scheduler);
 
 #if HAVE_SYSTEM
     StartupNotify(args);
diff --git a/src/kernel/chainstatemanager_opts.h b/src/kernel/chainstatemanager_opts.h
index 864aac336ed..de5f78494a2 100644
--- a/src/kernel/chainstatemanager_opts.h
+++ b/src/kernel/chainstatemanager_opts.h
@@ -18,6 +18,7 @@
 #include <optional>
 
 class CChainParams;
+class ValidationSignals;
 
 static constexpr bool DEFAULT_CHECKPOINTS_ENABLED{true};
 static constexpr auto DEFAULT_MAX_TIP_AGE{24h};
@@ -44,6 +45,7 @@ struct ChainstateManagerOpts {
     DBOptions coins_db{};
     CoinsViewOptions coins_view{};
     Notifications& notifications;
+    ValidationSignals* signals{nullptr};
     //! Number of script check worker threads. Zero means no parallel verification.
     int worker_threads_num{0};
 };
diff --git a/src/kernel/mempool_options.h b/src/kernel/mempool_options.h
index 753aebd4553..0850b2e60e1 100644
--- a/src/kernel/mempool_options.h
+++ b/src/kernel/mempool_options.h
@@ -13,6 +13,8 @@
 #include <cstdint>
 #include <optional>
 
+class ValidationSignals;
+
 /** Default for -maxmempool, maximum megabytes of mempool memory usage */
 static constexpr unsigned int DEFAULT_MAX_MEMPOOL_SIZE_MB{300};
 /** Default for -maxmempool when blocksonly is set */
@@ -56,6 +58,8 @@ struct MemPoolOptions {
     bool full_rbf{DEFAULT_MEMPOOL_FULL_RBF};
     bool persist_v1_dat{DEFAULT_PERSIST_V1_DAT};
     MemPoolLimits limits{};
+
+    ValidationSignals* signals{nullptr};
 };
 } // namespace kernel
 
diff --git a/src/node/context.h b/src/node/context.h
index 4f3b640b2d2..245f230aece 100644
--- a/src/node/context.h
+++ b/src/node/context.h
@@ -20,6 +20,7 @@ class BanMan;
 class BaseIndex;
 class CBlockPolicyEstimator;
 class CConnman;
+class ValidationSignals;
 class CScheduler;
 class CTxMemPool;
 class ChainstateManager;
@@ -70,7 +71,10 @@ struct NodeContext {
     interfaces::WalletLoader* wallet_loader{nullptr};
     std::unique_ptr<CScheduler> scheduler;
     std::function<void()> rpc_interruption_point = [] {};
+    //! Issues blocking calls about sync status, errors and warnings
     std::unique_ptr<KernelNotifications> notifications;
+    //! Issues calls about blocks and transactions
+    std::unique_ptr<ValidationSignals> validation_signals;
     std::atomic<int> exit_status{EXIT_SUCCESS};
 
     //! Declare default constructor and destructor that are not inline, so code
diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
index 5a8b7fc1058..f9a372e3de9 100644
--- a/src/node/interfaces.cpp
+++ b/src/node/interfaces.cpp
@@ -460,19 +460,20 @@ public:
 class NotificationsHandlerImpl : public Handler
 {
 public:
-    explicit NotificationsHandlerImpl(std::shared_ptr<Chain::Notifications> notifications)
-        : m_proxy(std::make_shared<NotificationsProxy>(std::move(notifications)))
+    explicit NotificationsHandlerImpl(ValidationSignals& signals, std::shared_ptr<Chain::Notifications> notifications)
+        : m_signals{signals}, m_proxy{std::make_shared<NotificationsProxy>(std::move(notifications))}
     {
-        RegisterSharedValidationInterface(m_proxy);
+        m_signals.RegisterSharedValidationInterface(m_proxy);
     }
     ~NotificationsHandlerImpl() override { disconnect(); }
     void disconnect() override
     {
         if (m_proxy) {
-            UnregisterSharedValidationInterface(m_proxy);
+            m_signals.UnregisterSharedValidationInterface(m_proxy);
             m_proxy.reset();
         }
     }
+    ValidationSignals& m_signals;
     std::shared_ptr<NotificationsProxy> m_proxy;
 };
 
@@ -761,12 +762,12 @@ public:
     }
     std::unique_ptr<Handler> handleNotifications(std::shared_ptr<Notifications> notifications) override
     {
-        return std::make_unique<NotificationsHandlerImpl>(std::move(notifications));
+        return std::make_unique<NotificationsHandlerImpl>(validation_signals(), std::move(notifications));
     }
     void waitForNotificationsIfTipChanged(const uint256& old_tip) override
     {
         if (!old_tip.IsNull() && old_tip == WITH_LOCK(::cs_main, return chainman().ActiveChain().Tip()->GetBlockHash())) return;
-        SyncWithValidationInterfaceQueue();
+        validation_signals().SyncWithValidationInterfaceQueue();
     }
     std::unique_ptr<Handler> handleRpc(const CRPCCommand& command) override
     {
@@ -822,6 +823,7 @@ public:
     NodeContext* context() override { return &m_node; }
     ArgsManager& args() { return *Assert(m_node.args); }
     ChainstateManager& chainman() { return *Assert(m_node.chainman); }
+    ValidationSignals& validation_signals() { return *Assert(m_node.validation_signals); }
     NodeContext& m_node;
 };
 } // namespace
diff --git a/src/node/transaction.cpp b/src/node/transaction.cpp
index ef9a30a076a..b66a4f2f39e 100644
--- a/src/node/transaction.cpp
+++ b/src/node/transaction.cpp
@@ -92,7 +92,7 @@ TransactionError BroadcastTransaction(NodeContext& node, const CTransactionRef t
                 node.mempool->AddUnbroadcastTx(txid);
             }
 
-            if (wait_callback) {
+            if (wait_callback && node.validation_signals) {
                 // For transactions broadcast from outside the wallet, make sure
                 // that the wallet has been notified of the transaction before
                 // continuing.
@@ -101,7 +101,7 @@ TransactionError BroadcastTransaction(NodeContext& node, const CTransactionRef t
                 // with a transaction to/from their wallet, immediately call some
                 // wallet RPC, and get a stale result because callbacks have not
                 // yet been processed.
-                CallFunctionInValidationInterfaceQueue([&promise] {
+                node.validation_signals->CallFunctionInValidationInterfaceQueue([&promise] {
                     promise.set_value();
                 });
                 callback_set = true;
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 50908e9f968..dfdddeacead 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -395,7 +395,8 @@ static RPCHelpMan syncwithvalidationinterfacequeue()
                 },
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {
-    SyncWithValidationInterfaceQueue();
+    NodeContext& node = EnsureAnyNodeContext(request.context);
+    CHECK_NONFATAL(node.validation_signals)->SyncWithValidationInterfaceQueue();
     return UniValue::VNULL;
 },
     };
diff --git a/src/rpc/fees.cpp b/src/rpc/fees.cpp
index 57ba486ed90..f3345b4f1ca 100644
--- a/src/rpc/fees.cpp
+++ b/src/rpc/fees.cpp
@@ -4,6 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <core_io.h>
+#include <node/context.h>
 #include <policy/feerate.h>
 #include <policy/fees.h>
 #include <rpc/protocol.h>
@@ -21,10 +22,6 @@
 #include <cmath>
 #include <string>
 
-namespace node {
-struct NodeContext;
-}
-
 using node::NodeContext;
 
 static RPCHelpMan estimatesmartfee()
@@ -68,7 +65,7 @@ static RPCHelpMan estimatesmartfee()
             const NodeContext& node = EnsureAnyNodeContext(request.context);
             const CTxMemPool& mempool = EnsureMemPool(node);
 
-            SyncWithValidationInterfaceQueue();
+            CHECK_NONFATAL(mempool.m_signals)->SyncWithValidationInterfaceQueue();
             unsigned int max_target = fee_estimator.HighestTargetTracked(FeeEstimateHorizon::LONG_HALFLIFE);
             unsigned int conf_target = ParseConfirmTarget(request.params[0], max_target);
             bool conservative = true;
@@ -156,8 +153,9 @@ static RPCHelpMan estimaterawfee()
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
         {
             CBlockPolicyEstimator& fee_estimator = EnsureAnyFeeEstimator(request.context);
+            const NodeContext& node = EnsureAnyNodeContext(request.context);
 
-            SyncWithValidationInterfaceQueue();
+            CHECK_NONFATAL(node.validation_signals)->SyncWithValidationInterfaceQueue();
             unsigned int max_target = fee_estimator.HighestTargetTracked(FeeEstimateHorizon::LONG_HALFLIFE);
             unsigned int conf_target = ParseConfirmTarget(request.params[0], max_target);
             double threshold = 0.95;
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index ff39a31a438..f7cdbf52dd0 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -1042,9 +1042,9 @@ static RPCHelpMan submitblock()
 
     bool new_block;
     auto sc = std::make_shared<submitblock_StateCatcher>(block.GetHash());
-    RegisterSharedValidationInterface(sc);
+    CHECK_NONFATAL(chainman.m_options.signals)->RegisterSharedValidationInterface(sc);
     bool accepted = chainman.ProcessNewBlock(blockptr, /*force_processing=*/true, /*min_pow_checked=*/true, /*new_block=*/&new_block);
-    UnregisterSharedValidationInterface(sc);
+    CHECK_NONFATAL(chainman.m_options.signals)->UnregisterSharedValidationInterface(sc);
     if (!new_block && accepted) {
         return "duplicate";
     }
diff --git a/src/rpc/node.cpp b/src/rpc/node.cpp
index 45053f882dd..b8c0080aefa 100644
--- a/src/rpc/node.cpp
+++ b/src/rpc/node.cpp
@@ -94,7 +94,7 @@ static RPCHelpMan mockscheduler()
 
     const NodeContext& node_context{EnsureAnyNodeContext(request.context)};
     CHECK_NONFATAL(node_context.scheduler)->MockForward(std::chrono::seconds{delta_seconds});
-    SyncWithValidationInterfaceQueue();
+    CHECK_NONFATAL(node_context.validation_signals)->SyncWithValidationInterfaceQueue();
     for (const auto& chain_client : node_context.chain_clients) {
         chain_client->schedulerMockForward(std::chrono::seconds(delta_seconds));
     }
diff --git a/src/scheduler.cpp b/src/scheduler.cpp
index 6c6f644142c..a1158e0c079 100644
--- a/src/scheduler.cpp
+++ b/src/scheduler.cpp
@@ -129,7 +129,7 @@ bool CScheduler::AreThreadsServicingQueue() const
 }
 
 
-void SingleThreadedSchedulerClient::MaybeScheduleProcessQueue()
+void SerialTaskRunner::MaybeScheduleProcessQueue()
 {
     {
         LOCK(m_callbacks_mutex);
@@ -142,7 +142,7 @@ void SingleThreadedSchedulerClient::MaybeScheduleProcessQueue()
     m_scheduler.schedule([this] { this->ProcessQueue(); }, std::chrono::steady_clock::now());
 }
 
-void SingleThreadedSchedulerClient::ProcessQueue()
+void SerialTaskRunner::ProcessQueue()
 {
     std::function<void()> callback;
     {
@@ -158,8 +158,8 @@ void SingleThreadedSchedulerClient::ProcessQueue()
     // RAII the setting of fCallbacksRunning and calling MaybeScheduleProcessQueue
     // to ensure both happen safely even if callback() throws.
     struct RAIICallbacksRunning {
-        SingleThreadedSchedulerClient* instance;
-        explicit RAIICallbacksRunning(SingleThreadedSchedulerClient* _instance) : instance(_instance) {}
+        SerialTaskRunner* instance;
+        explicit RAIICallbacksRunning(SerialTaskRunner* _instance) : instance(_instance) {}
         ~RAIICallbacksRunning()
         {
             {
@@ -173,7 +173,7 @@ void SingleThreadedSchedulerClient::ProcessQueue()
     callback();
 }
 
-void SingleThreadedSchedulerClient::AddToProcessQueue(std::function<void()> func)
+void SerialTaskRunner::insert(std::function<void()> func)
 {
     {
         LOCK(m_callbacks_mutex);
@@ -182,7 +182,7 @@ void SingleThreadedSchedulerClient::AddToProcessQueue(std::function<void()> func
     MaybeScheduleProcessQueue();
 }
 
-void SingleThreadedSchedulerClient::EmptyQueue()
+void SerialTaskRunner::flush()
 {
     assert(!m_scheduler.AreThreadsServicingQueue());
     bool should_continue = true;
@@ -193,7 +193,7 @@ void SingleThreadedSchedulerClient::EmptyQueue()
     }
 }
 
-size_t SingleThreadedSchedulerClient::CallbacksPending()
+size_t SerialTaskRunner::size()
 {
     LOCK(m_callbacks_mutex);
     return m_callbacks_pending.size();
diff --git a/src/scheduler.h b/src/scheduler.h
index 9212582b978..454c083b316 100644
--- a/src/scheduler.h
+++ b/src/scheduler.h
@@ -8,6 +8,7 @@
 #include <attributes.h>
 #include <sync.h>
 #include <threadsafety.h>
+#include <util/task_runner.h>
 
 #include <chrono>
 #include <condition_variable>
@@ -120,12 +121,16 @@ private:
  * B() will be able to observe all of the effects of callback A() which executed
  * before it.
  */
-class SingleThreadedSchedulerClient
+class SerialTaskRunner : public util::TaskRunnerInterface
 {
 private:
     CScheduler& m_scheduler;
 
     Mutex m_callbacks_mutex;
+
+    // We are not allowed to assume the scheduler only runs in one thread,
+    // but must ensure all callbacks happen in-order, so we end up creating
+    // our own queue here :(
     std::list<std::function<void()>> m_callbacks_pending GUARDED_BY(m_callbacks_mutex);
     bool m_are_callbacks_running GUARDED_BY(m_callbacks_mutex) = false;
 
@@ -133,7 +138,7 @@ private:
     void ProcessQueue() EXCLUSIVE_LOCKS_REQUIRED(!m_callbacks_mutex);
 
 public:
-    explicit SingleThreadedSchedulerClient(CScheduler& scheduler LIFETIMEBOUND) : m_scheduler{scheduler} {}
+    explicit SerialTaskRunner(CScheduler& scheduler LIFETIMEBOUND) : m_scheduler{scheduler} {}
 
     /**
      * Add a callback to be executed. Callbacks are executed serially
@@ -141,15 +146,15 @@ public:
      * Practically, this means that callbacks can behave as if they are executed
      * in order by a single thread.
      */
-    void AddToProcessQueue(std::function<void()> func) EXCLUSIVE_LOCKS_REQUIRED(!m_callbacks_mutex);
+    void insert(std::function<void()> func) override EXCLUSIVE_LOCKS_REQUIRED(!m_callbacks_mutex);
 
     /**
      * Processes all remaining queue members on the calling thread, blocking until queue is empty
      * Must be called after the CScheduler has no remaining processing threads!
      */
-    void EmptyQueue() EXCLUSIVE_LOCKS_REQUIRED(!m_callbacks_mutex);
+    void flush() override EXCLUSIVE_LOCKS_REQUIRED(!m_callbacks_mutex);
 
-    size_t CallbacksPending() EXCLUSIVE_LOCKS_REQUIRED(!m_callbacks_mutex);
+    size_t size() override EXCLUSIVE_LOCKS_REQUIRED(!m_callbacks_mutex);
 };
 
 #endif // BITCOIN_SCHEDULER_H
diff --git a/src/test/coinstatsindex_tests.cpp b/src/test/coinstatsindex_tests.cpp
index cc1ec49d41d..08814c1499d 100644
--- a/src/test/coinstatsindex_tests.cpp
+++ b/src/test/coinstatsindex_tests.cpp
@@ -70,7 +70,7 @@ BOOST_FIXTURE_TEST_CASE(coinstatsindex_initial_sync, TestChain100Setup)
     // SyncWithValidationInterfaceQueue() call below is also needed to ensure
     // TSAN always sees the test thread waiting for the notification thread, and
     // avoid potential false positive reports.
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
     // Shutdown sequence (c.f. Shutdown() in init.cpp)
     coin_stats_index.Stop();
diff --git a/src/test/fuzz/package_eval.cpp b/src/test/fuzz/package_eval.cpp
index 9e658e0ceda..a48ce37bce2 100644
--- a/src/test/fuzz/package_eval.cpp
+++ b/src/test/fuzz/package_eval.cpp
@@ -47,7 +47,7 @@ void initialize_tx_pool()
             g_outpoints_coinbase_init_mature.push_back(prevout);
         }
     }
-    SyncWithValidationInterfaceQueue();
+    g_setup->m_node.validation_signals->SyncWithValidationInterfaceQueue();
 }
 
 struct OutpointsUpdater final : public CValidationInterface {
@@ -147,7 +147,7 @@ FUZZ_TARGET(tx_package_eval, .init = initialize_tx_pool)
     }
 
     auto outpoints_updater = std::make_shared<OutpointsUpdater>(mempool_outpoints);
-    RegisterSharedValidationInterface(outpoints_updater);
+    node.validation_signals->RegisterSharedValidationInterface(outpoints_updater);
 
     CTxMemPool tx_pool_{MakeMempool(fuzzed_data_provider, node)};
     MockedTxPool& tx_pool = *static_cast<MockedTxPool*>(&tx_pool_);
@@ -269,7 +269,7 @@ FUZZ_TARGET(tx_package_eval, .init = initialize_tx_pool)
         // Remember all added transactions
         std::set<CTransactionRef> added;
         auto txr = std::make_shared<TransactionsDelta>(added);
-        RegisterSharedValidationInterface(txr);
+        node.validation_signals->RegisterSharedValidationInterface(txr);
 
         // When there are multiple transactions in the package, we call ProcessNewPackage(txs, test_accept=false)
         // and AcceptToMemoryPool(txs.back(), test_accept=true). When there is only 1 transaction, we might flip it
@@ -285,8 +285,8 @@ FUZZ_TARGET(tx_package_eval, .init = initialize_tx_pool)
                                    /*bypass_limits=*/false, /*test_accept=*/!single_submit));
         const bool passed = res.m_result_type == MempoolAcceptResult::ResultType::VALID;
 
-        SyncWithValidationInterfaceQueue();
-        UnregisterSharedValidationInterface(txr);
+        node.validation_signals->SyncWithValidationInterfaceQueue();
+        node.validation_signals->UnregisterSharedValidationInterface(txr);
 
         // There is only 1 transaction in the package. We did a test-package-accept and a ATMP
         if (single_submit) {
@@ -310,7 +310,7 @@ FUZZ_TARGET(tx_package_eval, .init = initialize_tx_pool)
         CheckMempoolV3Invariants(tx_pool);
     }
 
-    UnregisterSharedValidationInterface(outpoints_updater);
+    node.validation_signals->UnregisterSharedValidationInterface(outpoints_updater);
 
     WITH_LOCK(::cs_main, tx_pool.check(chainstate.CoinsTip(), chainstate.m_chain.Height() + 1));
 }
diff --git a/src/test/fuzz/process_message.cpp b/src/test/fuzz/process_message.cpp
index 56b391ed5c8..a467fd53820 100644
--- a/src/test/fuzz/process_message.cpp
+++ b/src/test/fuzz/process_message.cpp
@@ -47,7 +47,7 @@ void initialize_process_message()
     for (int i = 0; i < 2 * COINBASE_MATURITY; i++) {
         MineBlock(g_setup->m_node, CScript() << OP_TRUE);
     }
-    SyncWithValidationInterfaceQueue();
+    g_setup->m_node.validation_signals->SyncWithValidationInterfaceQueue();
 }
 
 FUZZ_TARGET(process_message, .init = initialize_process_message)
@@ -89,6 +89,6 @@ FUZZ_TARGET(process_message, .init = initialize_process_message)
         }
         g_setup->m_node.peerman->SendMessages(&p2p_node);
     }
-    SyncWithValidationInterfaceQueue();
+    g_setup->m_node.validation_signals->SyncWithValidationInterfaceQueue();
     g_setup->m_node.connman->StopNodes();
 }
diff --git a/src/test/fuzz/process_messages.cpp b/src/test/fuzz/process_messages.cpp
index 6b264907b5a..38acd432fa1 100644
--- a/src/test/fuzz/process_messages.cpp
+++ b/src/test/fuzz/process_messages.cpp
@@ -37,7 +37,7 @@ void initialize_process_messages()
     for (int i = 0; i < 2 * COINBASE_MATURITY; i++) {
         MineBlock(g_setup->m_node, CScript() << OP_TRUE);
     }
-    SyncWithValidationInterfaceQueue();
+    g_setup->m_node.validation_signals->SyncWithValidationInterfaceQueue();
 }
 
 FUZZ_TARGET(process_messages, .init = initialize_process_messages)
@@ -89,6 +89,6 @@ FUZZ_TARGET(process_messages, .init = initialize_process_messages)
             g_setup->m_node.peerman->SendMessages(&random_node);
         }
     }
-    SyncWithValidationInterfaceQueue();
+    g_setup->m_node.validation_signals->SyncWithValidationInterfaceQueue();
     g_setup->m_node.connman->StopNodes();
 }
diff --git a/src/test/fuzz/tx_pool.cpp b/src/test/fuzz/tx_pool.cpp
index fcf230642a6..b6ba612a84d 100644
--- a/src/test/fuzz/tx_pool.cpp
+++ b/src/test/fuzz/tx_pool.cpp
@@ -50,7 +50,7 @@ void initialize_tx_pool()
                               g_outpoints_coinbase_init_immature;
         outpoints.push_back(prevout);
     }
-    SyncWithValidationInterfaceQueue();
+    g_setup->m_node.validation_signals->SyncWithValidationInterfaceQueue();
 }
 
 struct TransactionsDelta final : public CValidationInterface {
@@ -105,7 +105,7 @@ void Finish(FuzzedDataProvider& fuzzed_data_provider, MockedTxPool& tx_pool, Cha
         assert(tx_pool.size() < info_all.size());
         WITH_LOCK(::cs_main, tx_pool.check(chainstate.CoinsTip(), chainstate.m_chain.Height() + 1));
     }
-    SyncWithValidationInterfaceQueue();
+    g_setup->m_node.validation_signals->SyncWithValidationInterfaceQueue();
 }
 
 void MockTime(FuzzedDataProvider& fuzzed_data_provider, const Chainstate& chainstate)
@@ -285,7 +285,7 @@ FUZZ_TARGET(tx_pool_standard, .init = initialize_tx_pool)
         std::set<CTransactionRef> removed;
         std::set<CTransactionRef> added;
         auto txr = std::make_shared<TransactionsDelta>(removed, added);
-        RegisterSharedValidationInterface(txr);
+        node.validation_signals->RegisterSharedValidationInterface(txr);
         const bool bypass_limits = fuzzed_data_provider.ConsumeBool();
 
         // Make sure ProcessNewPackage on one transaction works.
@@ -303,8 +303,8 @@ FUZZ_TARGET(tx_pool_standard, .init = initialize_tx_pool)
 
         const auto res = WITH_LOCK(::cs_main, return AcceptToMemoryPool(chainstate, tx, GetTime(), bypass_limits, /*test_accept=*/false));
         const bool accepted = res.m_result_type == MempoolAcceptResult::ResultType::VALID;
-        SyncWithValidationInterfaceQueue();
-        UnregisterSharedValidationInterface(txr);
+        node.validation_signals->SyncWithValidationInterfaceQueue();
+        node.validation_signals->UnregisterSharedValidationInterface(txr);
 
         bool txid_in_mempool = tx_pool.exists(GenTxid::Txid(tx->GetHash()));
         bool wtxid_in_mempool = tx_pool.exists(GenTxid::Wtxid(tx->GetWitnessHash()));
diff --git a/src/test/peerman_tests.cpp b/src/test/peerman_tests.cpp
index 2c793293854..28866695bc6 100644
--- a/src/test/peerman_tests.cpp
+++ b/src/test/peerman_tests.cpp
@@ -25,7 +25,7 @@ static void mineBlock(const node::NodeContext& node, std::chrono::seconds block_
     block.fChecked = true; // little speedup
     SetMockTime(curr_time); // process block at current time
     Assert(node.chainman->ProcessNewBlock(std::make_shared<const CBlock>(block), /*force_processing=*/true, /*min_pow_checked=*/true, nullptr));
-    SyncWithValidationInterfaceQueue(); // drain events queue
+    node.validation_signals->SyncWithValidationInterfaceQueue(); // drain events queue
 }
 
 // Verifying when network-limited peer connections are desirable based on the node's proximity to the tip
@@ -57,7 +57,7 @@ BOOST_AUTO_TEST_CASE(connections_desirable_service_flags)
 
     // By now, we tested that the connections desirable services flags change based on the node's time proximity to the tip.
     // Now, perform the same tests for when the node receives a block.
-    RegisterValidationInterface(peerman.get());
+    m_node.validation_signals->RegisterValidationInterface(peerman.get());
 
     // First, verify a block in the past doesn't enable limited peers connections
     // At this point, our time is (NODE_NETWORK_LIMITED_ALLOW_CONN_BLOCKS + 1) * 10 minutes ahead the tip's time.
diff --git a/src/test/policyestimator_tests.cpp b/src/test/policyestimator_tests.cpp
index ede73c68957..6cadc3290a5 100644
--- a/src/test/policyestimator_tests.cpp
+++ b/src/test/policyestimator_tests.cpp
@@ -20,7 +20,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
 {
     CBlockPolicyEstimator& feeEst = *Assert(m_node.fee_estimator);
     CTxMemPool& mpool = *Assert(m_node.mempool);
-    RegisterValidationInterface(&feeEst);
+    m_node.validation_signals->RegisterValidationInterface(&feeEst);
     TestMemPoolEntryHelper entry;
     CAmount basefee(2000);
     CAmount deltaFee(100);
@@ -74,7 +74,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
                                                                                       /*submitted_in_package=*/false,
                                                                                       /*chainstate_is_current=*/true,
                                                                                       /*has_no_mempool_parents=*/true)};
-                    GetMainSignals().TransactionAddedToMempool(tx_info, mpool.GetAndIncrementSequence());
+                    m_node.validation_signals->TransactionAddedToMempool(tx_info, mpool.GetAndIncrementSequence());
                 }
                 uint256 hash = tx.GetHash();
                 txHashes[j].push_back(hash);
@@ -102,7 +102,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
         // Check after just a few txs that combining buckets works as expected
         if (blocknum == 3) {
             // Wait for fee estimator to catch up
-            SyncWithValidationInterfaceQueue();
+            m_node.validation_signals->SyncWithValidationInterfaceQueue();
             // At this point we should need to combine 3 buckets to get enough data points
             // So estimateFee(1) should fail and estimateFee(2) should return somewhere around
             // 9*baserate.  estimateFee(2) %'s are 100,100,90 = average 97%
@@ -113,7 +113,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
     }
 
     // Wait for fee estimator to catch up
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
     std::vector<CAmount> origFeeEst;
     // Highest feerate is 10*baseRate and gets in all blocks,
@@ -146,7 +146,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
     }
 
     // Wait for fee estimator to catch up
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
     BOOST_CHECK(feeEst.estimateFee(1) == CFeeRate(0));
     for (int i = 2; i < 10;i++) {
@@ -175,7 +175,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
                                                                                       /*submitted_in_package=*/false,
                                                                                       /*chainstate_is_current=*/true,
                                                                                       /*has_no_mempool_parents=*/true)};
-                    GetMainSignals().TransactionAddedToMempool(tx_info, mpool.GetAndIncrementSequence());
+                    m_node.validation_signals->TransactionAddedToMempool(tx_info, mpool.GetAndIncrementSequence());
                 }
                 uint256 hash = tx.GetHash();
                 txHashes[j].push_back(hash);
@@ -188,7 +188,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
     }
 
     // Wait for fee estimator to catch up
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
     for (int i = 1; i < 10;i++) {
         BOOST_CHECK(feeEst.estimateFee(i) == CFeeRate(0) || feeEst.estimateFee(i).GetFeePerK() > origFeeEst[i-1] - deltaFee);
@@ -212,7 +212,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
     block.clear();
 
     // Wait for fee estimator to catch up
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
     BOOST_CHECK(feeEst.estimateFee(1) == CFeeRate(0));
     for (int i = 2; i < 10;i++) {
@@ -239,7 +239,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
                                                                                       /*submitted_in_package=*/false,
                                                                                       /*chainstate_is_current=*/true,
                                                                                       /*has_no_mempool_parents=*/true)};
-                    GetMainSignals().TransactionAddedToMempool(tx_info, mpool.GetAndIncrementSequence());
+                    m_node.validation_signals->TransactionAddedToMempool(tx_info, mpool.GetAndIncrementSequence());
                 }
                 uint256 hash = tx.GetHash();
                 CTransactionRef ptx = mpool.get(hash);
@@ -257,7 +257,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
         block.clear();
     }
     // Wait for fee estimator to catch up
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
     BOOST_CHECK(feeEst.estimateFee(1) == CFeeRate(0));
     for (int i = 2; i < 9; i++) { // At 9, the original estimate was already at the bottom (b/c scale = 2)
         BOOST_CHECK(feeEst.estimateFee(i).GetFeePerK() < origFeeEst[i-1] - deltaFee);
diff --git a/src/test/scheduler_tests.cpp b/src/test/scheduler_tests.cpp
index 3fb33785982..95e725de468 100644
--- a/src/test/scheduler_tests.cpp
+++ b/src/test/scheduler_tests.cpp
@@ -129,8 +129,8 @@ BOOST_AUTO_TEST_CASE(singlethreadedscheduler_ordered)
     CScheduler scheduler;
 
     // each queue should be well ordered with respect to itself but not other queues
-    SingleThreadedSchedulerClient queue1(scheduler);
-    SingleThreadedSchedulerClient queue2(scheduler);
+    SerialTaskRunner queue1(scheduler);
+    SerialTaskRunner queue2(scheduler);
 
     // create more threads than queues
     // if the queues only permit execution of one task at once then
@@ -142,7 +142,7 @@ BOOST_AUTO_TEST_CASE(singlethreadedscheduler_ordered)
         threads.emplace_back([&] { scheduler.serviceQueue(); });
     }
 
-    // these are not atomic, if SinglethreadedSchedulerClient prevents
+    // these are not atomic, if SerialTaskRunner prevents
     // parallel execution at the queue level no synchronization should be required here
     int counter1 = 0;
     int counter2 = 0;
@@ -150,12 +150,12 @@ BOOST_AUTO_TEST_CASE(singlethreadedscheduler_ordered)
     // just simply count up on each queue - if execution is properly ordered then
     // the callbacks should run in exactly the order in which they were enqueued
     for (int i = 0; i < 100; ++i) {
-        queue1.AddToProcessQueue([i, &counter1]() {
+        queue1.insert([i, &counter1]() {
             bool expectation = i == counter1++;
             assert(expectation);
         });
 
-        queue2.AddToProcessQueue([i, &counter2]() {
+        queue2.insert([i, &counter2]() {
             bool expectation = i == counter2++;
             assert(expectation);
         });
diff --git a/src/test/txindex_tests.cpp b/src/test/txindex_tests.cpp
index e2432a4718e..5a32b02ad9c 100644
--- a/src/test/txindex_tests.cpp
+++ b/src/test/txindex_tests.cpp
@@ -71,7 +71,7 @@ BOOST_FIXTURE_TEST_CASE(txindex_initial_sync, TestChain100Setup)
     // SyncWithValidationInterfaceQueue() call below is also needed to ensure
     // TSAN always sees the test thread waiting for the notification thread, and
     // avoid potential false positive reports.
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
     // shutdown sequence (c.f. Shutdown() in init.cpp)
     txindex.Stop();
diff --git a/src/test/util/mining.cpp b/src/test/util/mining.cpp
index 08d1b4c9028..ad7a38d3fea 100644
--- a/src/test/util/mining.cpp
+++ b/src/test/util/mining.cpp
@@ -95,12 +95,12 @@ COutPoint MineBlock(const NodeContext& node, std::shared_ptr<CBlock>& block)
     const auto old_height = WITH_LOCK(chainman.GetMutex(), return chainman.ActiveHeight());
     bool new_block;
     BlockValidationStateCatcher bvsc{block->GetHash()};
-    RegisterValidationInterface(&bvsc);
+    node.validation_signals->RegisterValidationInterface(&bvsc);
     const bool processed{chainman.ProcessNewBlock(block, true, true, &new_block)};
     const bool duplicate{!new_block && processed};
     assert(!duplicate);
-    UnregisterValidationInterface(&bvsc);
-    SyncWithValidationInterfaceQueue();
+    node.validation_signals->UnregisterValidationInterface(&bvsc);
+    node.validation_signals->SyncWithValidationInterfaceQueue();
     const bool was_valid{bvsc.m_state && bvsc.m_state->IsValid()};
     assert(old_height + was_valid == WITH_LOCK(chainman.GetMutex(), return chainman.ActiveHeight()));
 
diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index 1f8dbac5bed..d26a4400747 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -175,7 +175,7 @@ ChainTestingSetup::ChainTestingSetup(const ChainType chainType, const std::vecto
     // from blocking due to queue overrun.
     m_node.scheduler = std::make_unique<CScheduler>();
     m_node.scheduler->m_service_thread = std::thread(util::TraceThread, "scheduler", [&] { m_node.scheduler->serviceQueue(); });
-    GetMainSignals().RegisterBackgroundSignalScheduler(*m_node.scheduler);
+    m_node.validation_signals = std::make_unique<ValidationSignals>(std::make_unique<SerialTaskRunner>(*m_node.scheduler));
 
     m_node.fee_estimator = std::make_unique<CBlockPolicyEstimator>(FeeestPath(*m_node.args), DEFAULT_ACCEPT_STALE_FEE_ESTIMATES);
     m_node.mempool = std::make_unique<CTxMemPool>(MemPoolOptionsForTest(m_node));
@@ -189,6 +189,7 @@ ChainTestingSetup::ChainTestingSetup(const ChainType chainType, const std::vecto
         .datadir = m_args.GetDataDirNet(),
         .check_block_index = true,
         .notifications = *m_node.notifications,
+        .signals = m_node.validation_signals.get(),
         .worker_threads_num = 2,
     };
     const BlockManager::Options blockman_opts{
@@ -206,8 +207,7 @@ ChainTestingSetup::ChainTestingSetup(const ChainType chainType, const std::vecto
 ChainTestingSetup::~ChainTestingSetup()
 {
     if (m_node.scheduler) m_node.scheduler->stop();
-    GetMainSignals().FlushBackgroundCallbacks();
-    GetMainSignals().UnregisterBackgroundSignalScheduler();
+    m_node.validation_signals->FlushBackgroundCallbacks();
     m_node.connman.reset();
     m_node.banman.reset();
     m_node.addrman.reset();
@@ -216,6 +216,7 @@ ChainTestingSetup::~ChainTestingSetup()
     m_node.mempool.reset();
     m_node.fee_estimator.reset();
     m_node.chainman.reset();
+    m_node.validation_signals.reset();
     m_node.scheduler.reset();
 }
 
diff --git a/src/test/util/txmempool.cpp b/src/test/util/txmempool.cpp
index 3b4161ddd3c..71cf8aca605 100644
--- a/src/test/util/txmempool.cpp
+++ b/src/test/util/txmempool.cpp
@@ -22,6 +22,7 @@ CTxMemPool::Options MemPoolOptionsForTest(const NodeContext& node)
         // Default to always checking mempool regardless of
         // chainparams.DefaultConsistencyChecks for tests
         .check_ratio = 1,
+        .signals = node.validation_signals.get(),
     };
     const auto result{ApplyArgsManOptions(*node.args, ::Params(), mempool_opts)};
     Assert(result);
diff --git a/src/test/validation_block_tests.cpp b/src/test/validation_block_tests.cpp
index 35e5c6a0372..316ab86c2b3 100644
--- a/src/test/validation_block_tests.cpp
+++ b/src/test/validation_block_tests.cpp
@@ -158,7 +158,7 @@ BOOST_AUTO_TEST_CASE(processnewblock_signals_ordering)
     bool ignored;
     // Connect the genesis block and drain any outstanding events
     BOOST_CHECK(Assert(m_node.chainman)->ProcessNewBlock(std::make_shared<CBlock>(Params().GenesisBlock()), true, true, &ignored));
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
     // subscribe to events (this subscriber will validate event ordering)
     const CBlockIndex* initial_tip = nullptr;
@@ -167,7 +167,7 @@ BOOST_AUTO_TEST_CASE(processnewblock_signals_ordering)
         initial_tip = m_node.chainman->ActiveChain().Tip();
     }
     auto sub = std::make_shared<TestSubscriber>(initial_tip->GetBlockHash());
-    RegisterSharedValidationInterface(sub);
+    m_node.validation_signals->RegisterSharedValidationInterface(sub);
 
     // create a bunch of threads that repeatedly process a block generated above at random
     // this will create parallelism and randomness inside validation - the ValidationInterface
@@ -196,9 +196,9 @@ BOOST_AUTO_TEST_CASE(processnewblock_signals_ordering)
     for (auto& t : threads) {
         t.join();
     }
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
-    UnregisterSharedValidationInterface(sub);
+    m_node.validation_signals->UnregisterSharedValidationInterface(sub);
 
     LOCK(cs_main);
     BOOST_CHECK_EQUAL(sub->m_expected_tip, m_node.chainman->ActiveChain().Tip()->GetBlockHash());
diff --git a/src/test/validation_chainstatemanager_tests.cpp b/src/test/validation_chainstatemanager_tests.cpp
index a33e71d50ee..4bbab1cdcd2 100644
--- a/src/test/validation_chainstatemanager_tests.cpp
+++ b/src/test/validation_chainstatemanager_tests.cpp
@@ -102,7 +102,7 @@ BOOST_FIXTURE_TEST_CASE(chainstatemanager, TestChain100Setup)
     BOOST_CHECK_EQUAL(active_tip2, c2.m_chain.Tip());
 
     // Let scheduler events finish running to avoid accessing memory that is going to be unloaded
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 }
 
 //! Test rebalancing the caches associated with each chainstate.
@@ -374,7 +374,7 @@ struct SnapshotTestSetup : TestChain100Setup {
                 cs->ForceFlushStateToDisk();
             }
             // Process all callbacks referring to the old manager before wiping it.
-            SyncWithValidationInterfaceQueue();
+            m_node.validation_signals->SyncWithValidationInterfaceQueue();
             LOCK(::cs_main);
             chainman.ResetChainstates();
             BOOST_CHECK_EQUAL(chainman.GetAll().size(), 0);
@@ -383,6 +383,7 @@ struct SnapshotTestSetup : TestChain100Setup {
                 .chainparams = ::Params(),
                 .datadir = chainman.m_options.datadir,
                 .notifications = *m_node.notifications,
+                .signals = m_node.validation_signals.get(),
             };
             const BlockManager::Options blockman_opts{
                 .chainparams = chainman_opts.chainparams,
diff --git a/src/test/validationinterface_tests.cpp b/src/test/validationinterface_tests.cpp
index 5979441057c..a46cfc30292 100644
--- a/src/test/validationinterface_tests.cpp
+++ b/src/test/validationinterface_tests.cpp
@@ -28,7 +28,7 @@ BOOST_AUTO_TEST_CASE(unregister_validation_interface_race)
         const CBlock block_dummy;
         BlockValidationState state_dummy;
         while (generate) {
-            GetMainSignals().BlockChecked(block_dummy, state_dummy);
+            m_node.validation_signals->BlockChecked(block_dummy, state_dummy);
         }
     }};
 
@@ -37,8 +37,8 @@ BOOST_AUTO_TEST_CASE(unregister_validation_interface_race)
         // keep going for about 1 sec, which is 250k iterations
         for (int i = 0; i < 250000; i++) {
             auto sub = std::make_shared<TestSubscriberNoop>();
-            RegisterSharedValidationInterface(sub);
-            UnregisterSharedValidationInterface(sub);
+            m_node.validation_signals->RegisterSharedValidationInterface(sub);
+            m_node.validation_signals->UnregisterSharedValidationInterface(sub);
         }
         // tell the other thread we are done
         generate = false;
@@ -52,8 +52,8 @@ BOOST_AUTO_TEST_CASE(unregister_validation_interface_race)
 class TestInterface : public CValidationInterface
 {
 public:
-    TestInterface(std::function<void()> on_call = nullptr, std::function<void()> on_destroy = nullptr)
-        : m_on_call(std::move(on_call)), m_on_destroy(std::move(on_destroy))
+    TestInterface(ValidationSignals& signals, std::function<void()> on_call = nullptr, std::function<void()> on_destroy = nullptr)
+        : m_on_call(std::move(on_call)), m_on_destroy(std::move(on_destroy)), m_signals{signals}
     {
     }
     virtual ~TestInterface()
@@ -64,14 +64,15 @@ public:
     {
         if (m_on_call) m_on_call();
     }
-    static void Call()
+    void Call()
     {
         CBlock block;
         BlockValidationState state;
-        GetMainSignals().BlockChecked(block, state);
+        m_signals.BlockChecked(block, state);
     }
     std::function<void()> m_on_call;
     std::function<void()> m_on_destroy;
+    ValidationSignals& m_signals;
 };
 
 // Regression test to ensure UnregisterAllValidationInterfaces calls don't
@@ -80,17 +81,23 @@ public:
 BOOST_AUTO_TEST_CASE(unregister_all_during_call)
 {
     bool destroyed = false;
-    RegisterSharedValidationInterface(std::make_shared<TestInterface>(
+    auto shared{std::make_shared<TestInterface>(
+        *m_node.validation_signals,
         [&] {
             // First call should decrements reference count 2 -> 1
-            UnregisterAllValidationInterfaces();
+            m_node.validation_signals->UnregisterAllValidationInterfaces();
             BOOST_CHECK(!destroyed);
             // Second call should not decrement reference count 1 -> 0
-            UnregisterAllValidationInterfaces();
+            m_node.validation_signals->UnregisterAllValidationInterfaces();
             BOOST_CHECK(!destroyed);
         },
-        [&] { destroyed = true; }));
-    TestInterface::Call();
+        [&] { destroyed = true; })};
+    m_node.validation_signals->RegisterSharedValidationInterface(shared);
+    BOOST_CHECK(shared.use_count() == 2);
+    shared->Call();
+    BOOST_CHECK(shared.use_count() == 1);
+    BOOST_CHECK(!destroyed);
+    shared.reset();
     BOOST_CHECK(destroyed);
 }
 
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index de340f6b6d7..0bee27c2b21 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -406,7 +406,8 @@ CTxMemPool::CTxMemPool(const Options& opts)
       m_require_standard{opts.require_standard},
       m_full_rbf{opts.full_rbf},
       m_persist_v1_dat{opts.persist_v1_dat},
-      m_limits{opts.limits}
+      m_limits{opts.limits},
+      m_signals{opts.signals}
 {
 }
 
@@ -487,12 +488,12 @@ void CTxMemPool::removeUnchecked(txiter it, MemPoolRemovalReason reason)
     // even if not directly reported below.
     uint64_t mempool_sequence = GetAndIncrementSequence();
 
-    if (reason != MemPoolRemovalReason::BLOCK) {
+    if (reason != MemPoolRemovalReason::BLOCK && m_signals) {
         // Notify clients that a transaction has been removed from the mempool
         // for any reason except being included in a block. Clients interested
         // in transactions included in blocks can subscribe to the BlockConnected
         // notification.
-        GetMainSignals().TransactionRemovedFromMempool(it->GetSharedTx(), reason, mempool_sequence);
+        m_signals->TransactionRemovedFromMempool(it->GetSharedTx(), reason, mempool_sequence);
     }
     TRACE5(mempool, removed,
         it->GetTx().GetHash().data(),
@@ -643,7 +644,9 @@ void CTxMemPool::removeForBlock(const std::vector<CTransactionRef>& vtx, unsigne
         removeConflicts(*tx);
         ClearPrioritisation(tx->GetHash());
     }
-    GetMainSignals().MempoolTransactionsRemovedForBlock(txs_removed_for_block, nBlockHeight);
+    if (m_signals) {
+        m_signals->MempoolTransactionsRemovedForBlock(txs_removed_for_block, nBlockHeight);
+    }
     lastRollingFeeUpdate = GetTime();
     blockSinceLastRollingFeeBump = true;
 }
diff --git a/src/txmempool.h b/src/txmempool.h
index b98355c65f1..32f2c024f76 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -40,6 +40,7 @@
 #include <vector>
 
 class CChain;
+class ValidationSignals;
 
 /** Fake height value used in Coin to signify they are only in the memory pool (since 0.8) */
 static const uint32_t MEMPOOL_HEIGHT = 0x7FFFFFFF;
@@ -447,6 +448,8 @@ public:
 
     const Limits m_limits;
 
+    ValidationSignals* const m_signals;
+
     /** Create a new CTxMemPool.
      * Sanity checks will be off by default for performance, because otherwise
      * accepting transactions becomes O(N^2) where N is the number of transactions
diff --git a/src/util/task_runner.h b/src/util/task_runner.h
new file mode 100644
index 00000000000..d3cd8007de9
--- /dev/null
+++ b/src/util/task_runner.h
@@ -0,0 +1,52 @@
+// Copyright (c) 2024-present The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_UTIL_TASK_RUNNER_H
+#define BITCOIN_UTIL_TASK_RUNNER_H
+
+#include <cstddef>
+#include <functional>
+
+namespace util {
+
+/** @file
+ * This header provides an interface and simple implementation for a task
+ * runner. Another threaded, serial implementation using a queue is available in
+ * the scheduler module's SerialTaskRunner.
+ */
+
+class TaskRunnerInterface
+{
+public:
+    virtual ~TaskRunnerInterface() {}
+
+    /**
+     * The callback can either be queued for later/asynchronous/threaded
+     * processing, or be executed immediately for synchronous processing.
+     */
+
+    virtual void insert(std::function<void()> func) = 0;
+
+    /**
+     * Forces the processing of all pending events.
+     */
+    virtual void flush() = 0;
+
+    /**
+     * Returns the number of currently pending events.
+     */
+    virtual size_t size() = 0;
+};
+
+class ImmediateTaskRunner : public TaskRunnerInterface
+{
+public:
+    void insert(std::function<void()> func) override { func(); }
+    void flush() override {}
+    size_t size() override { return 0; }
+};
+
+} // namespace util
+
+#endif // BITCOIN_UTIL_TASK_RUNNER_H
diff --git a/src/validation.cpp b/src/validation.cpp
index f8e1de55e9b..3a652adb1da 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1228,13 +1228,14 @@ bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>&
         results.emplace(ws.m_ptx->GetWitnessHash(),
                         MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), ws.m_vsize,
                                          ws.m_base_fees, effective_feerate, effective_feerate_wtxids));
+        if (!m_pool.m_signals) continue;
         const CTransaction& tx = *ws.m_ptx;
         const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees,
                                                        ws.m_vsize, ws.m_entry->GetHeight(),
                                                        args.m_bypass_limits, args.m_package_submission,
                                                        IsCurrentForFeeEstimation(m_active_chainstate),
                                                        m_pool.HasNoInputsOf(tx));
-        GetMainSignals().TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence());
+        m_pool.m_signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence());
     }
     return all_submitted;
 }
@@ -1242,7 +1243,7 @@ bool MemPoolAccept::SubmitPackage(const ATMPArgs& args, std::vector<Workspace>&
 MempoolAcceptResult MemPoolAccept::AcceptSingleTransaction(const CTransactionRef& ptx, ATMPArgs& args)
 {
     AssertLockHeld(cs_main);
-    LOCK(m_pool.cs); // mempool "read lock" (held through GetMainSignals().TransactionAddedToMempool())
+    LOCK(m_pool.cs); // mempool "read lock" (held through m_pool.m_signals->TransactionAddedToMempool())
 
     Workspace ws(ptx);
     const std::vector<Wtxid> single_wtxid{ws.m_ptx->GetWitnessHash()};
@@ -1277,13 +1278,15 @@ MempoolAcceptResult MemPoolAccept::AcceptSingleTransaction(const CTransactionRef
         return MempoolAcceptResult::FeeFailure(ws.m_state, CFeeRate(ws.m_modified_fees, ws.m_vsize), {ws.m_ptx->GetWitnessHash()});
     }
 
-    const CTransaction& tx = *ws.m_ptx;
-    const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees,
-                                                   ws.m_vsize, ws.m_entry->GetHeight(),
-                                                   args.m_bypass_limits, args.m_package_submission,
-                                                   IsCurrentForFeeEstimation(m_active_chainstate),
-                                                   m_pool.HasNoInputsOf(tx));
-    GetMainSignals().TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence());
+    if (m_pool.m_signals) {
+        const CTransaction& tx = *ws.m_ptx;
+        const auto tx_info = NewMempoolTransactionInfo(ws.m_ptx, ws.m_base_fees,
+                                                       ws.m_vsize, ws.m_entry->GetHeight(),
+                                                       args.m_bypass_limits, args.m_package_submission,
+                                                       IsCurrentForFeeEstimation(m_active_chainstate),
+                                                       m_pool.HasNoInputsOf(tx));
+        m_pool.m_signals->TransactionAddedToMempool(tx_info, m_pool.GetAndIncrementSequence());
+    }
 
     return MempoolAcceptResult::Success(std::move(ws.m_replaced_transactions), ws.m_vsize, ws.m_base_fees,
                                         effective_feerate, single_wtxid);
@@ -2695,9 +2698,9 @@ bool Chainstate::FlushStateToDisk(
                    (bool)fFlushForPrune);
         }
     }
-    if (full_flush_completed) {
+    if (full_flush_completed && m_chainman.m_options.signals) {
         // Update best block in wallet (so we can detect restored wallets).
-        GetMainSignals().ChainStateFlushed(this->GetRole(), m_chain.GetLocator());
+        m_chainman.m_options.signals->ChainStateFlushed(this->GetRole(), m_chain.GetLocator());
     }
     } catch (const std::runtime_error& e) {
         return FatalError(m_chainman.GetNotifications(), state, std::string("System error while flushing: ") + e.what());
@@ -2864,7 +2867,9 @@ bool Chainstate::DisconnectTip(BlockValidationState& state, DisconnectedBlockTra
     UpdateTip(pindexDelete->pprev);
     // Let wallets know transactions went from 1-confirmed to
     // 0-confirmed or conflicted:
-    GetMainSignals().BlockDisconnected(pblock, pindexDelete);
+    if (m_chainman.m_options.signals) {
+        m_chainman.m_options.signals->BlockDisconnected(pblock, pindexDelete);
+    }
     return true;
 }
 
@@ -2949,7 +2954,9 @@ bool Chainstate::ConnectTip(BlockValidationState& state, CBlockIndex* pindexNew,
     {
         CCoinsViewCache view(&CoinsTip());
         bool rv = ConnectBlock(blockConnecting, state, pindexNew, view);
-        GetMainSignals().BlockChecked(blockConnecting, state);
+        if (m_chainman.m_options.signals) {
+            m_chainman.m_options.signals->BlockChecked(blockConnecting, state);
+        }
         if (!rv) {
             if (state.IsInvalid())
                 InvalidBlockFound(pindexNew, state);
@@ -3210,11 +3217,11 @@ static bool NotifyHeaderTip(ChainstateManager& chainman) LOCKS_EXCLUDED(cs_main)
     return fNotify;
 }
 
-static void LimitValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main) {
+static void LimitValidationInterfaceQueue(ValidationSignals& signals) LOCKS_EXCLUDED(cs_main) {
     AssertLockNotHeld(cs_main);
 
-    if (GetMainSignals().CallbacksPending() > 10) {
-        SyncWithValidationInterfaceQueue();
+    if (signals.CallbacksPending() > 10) {
+        signals.SyncWithValidationInterfaceQueue();
     }
 }
 
@@ -3252,7 +3259,7 @@ bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<
         // Note that if a validationinterface callback ends up calling
         // ActivateBestChain this may lead to a deadlock! We should
         // probably have a DEBUG_LOCKORDER test for this in the future.
-        LimitValidationInterfaceQueue();
+        if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals);
 
         {
             LOCK(cs_main);
@@ -3291,7 +3298,9 @@ bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<
 
                 for (const PerBlockConnectTrace& trace : connectTrace.GetBlocksConnected()) {
                     assert(trace.pblock && trace.pindex);
-                    GetMainSignals().BlockConnected(this->GetRole(), trace.pblock, trace.pindex);
+                    if (m_chainman.m_options.signals) {
+                        m_chainman.m_options.signals->BlockConnected(this->GetRole(), trace.pblock, trace.pindex);
+                    }
                 }
 
                 // This will have been toggled in
@@ -3317,7 +3326,9 @@ bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<
             // Enqueue while holding cs_main to ensure that UpdatedBlockTip is called in the order in which blocks are connected
             if (this == &m_chainman.ActiveChainstate() && pindexFork != pindexNewTip) {
                 // Notify ValidationInterface subscribers
-                GetMainSignals().UpdatedBlockTip(pindexNewTip, pindexFork, still_in_ibd);
+                if (m_chainman.m_options.signals) {
+                    m_chainman.m_options.signals->UpdatedBlockTip(pindexNewTip, pindexFork, still_in_ibd);
+                }
 
                 // Always notify the UI if a new block tip was connected
                 if (kernel::IsInterrupted(m_chainman.GetNotifications().blockTip(GetSynchronizationState(still_in_ibd), *pindexNewTip))) {
@@ -3451,7 +3462,7 @@ bool Chainstate::InvalidateBlock(BlockValidationState& state, CBlockIndex* pinde
         if (m_chainman.m_interrupt) break;
 
         // Make sure the queue of validation callbacks doesn't grow unboundedly.
-        LimitValidationInterfaceQueue();
+        if (m_chainman.m_options.signals) LimitValidationInterfaceQueue(*m_chainman.m_options.signals);
 
         LOCK(cs_main);
         // Lock for as long as disconnectpool is in scope to make sure MaybeUpdateMempoolForReorg is
@@ -4237,8 +4248,9 @@ bool ChainstateManager::AcceptBlock(const std::shared_ptr<const CBlock>& pblock,
 
     // Header is valid/has work, merkle tree and segwit merkle tree are good...RELAY NOW
     // (but if it does not build on our best tip, let the SendMessages loop relay it)
-    if (!IsInitialBlockDownload() && ActiveTip() == pindex->pprev)
-        GetMainSignals().NewPoWValidBlock(pindex, pblock);
+    if (!IsInitialBlockDownload() && ActiveTip() == pindex->pprev && m_options.signals) {
+        m_options.signals->NewPoWValidBlock(pindex, pblock);
+    }
 
     // Write block to history file
     if (fNewBlock) *fNewBlock = true;
@@ -4291,7 +4303,9 @@ bool ChainstateManager::ProcessNewBlock(const std::shared_ptr<const CBlock>& blo
             ret = AcceptBlock(block, state, &pindex, force_processing, nullptr, new_block, min_pow_checked);
         }
         if (!ret) {
-            GetMainSignals().BlockChecked(*block, state);
+            if (m_options.signals) {
+                m_options.signals->BlockChecked(*block, state);
+            }
             return error("%s: AcceptBlock FAILED (%s)", __func__, state.ToString());
         }
     }
diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index 5e944a7c47d..813fde109c5 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -5,7 +5,6 @@
 
 #include <validationinterface.h>
 
-#include <attributes.h>
 #include <chain.h>
 #include <consensus/validation.h>
 #include <kernel/chain.h>
@@ -13,7 +12,8 @@
 #include <logging.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
-#include <scheduler.h>
+#include <util/check.h>
+#include <util/task_runner.h>
 
 #include <future>
 #include <unordered_map>
@@ -22,14 +22,14 @@
 std::string RemovalReasonToString(const MemPoolRemovalReason& r) noexcept;
 
 /**
- * MainSignalsImpl manages a list of shared_ptr<CValidationInterface> callbacks.
+ * ValidationSignalsImpl manages a list of shared_ptr<CValidationInterface> callbacks.
  *
  * A std::unordered_map is used to track what callbacks are currently
  * registered, and a std::list is used to store the callbacks that are
  * currently registered as well as any callbacks that are just unregistered
  * and about to be deleted when they are done executing.
  */
-class MainSignalsImpl
+class ValidationSignalsImpl
 {
 private:
     Mutex m_mutex;
@@ -42,12 +42,10 @@ private:
     std::unordered_map<CValidationInterface*, std::list<ListEntry>::iterator> m_map GUARDED_BY(m_mutex);
 
 public:
-    // We are not allowed to assume the scheduler only runs in one thread,
-    // but must ensure all callbacks happen in-order, so we end up creating
-    // our own queue here :(
-    SingleThreadedSchedulerClient m_schedulerClient;
+    std::unique_ptr<util::TaskRunnerInterface> m_task_runner;
 
-    explicit MainSignalsImpl(CScheduler& scheduler LIFETIMEBOUND) : m_schedulerClient(scheduler) {}
+    explicit ValidationSignalsImpl(std::unique_ptr<util::TaskRunnerInterface> task_runner)
+        : m_task_runner{std::move(Assert(task_runner))} {}
 
     void Register(std::shared_ptr<CValidationInterface> callbacks) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
     {
@@ -94,77 +92,56 @@ public:
     }
 };
 
-static CMainSignals g_signals;
+ValidationSignals::ValidationSignals(std::unique_ptr<util::TaskRunnerInterface> task_runner)
+    : m_internals{std::make_unique<ValidationSignalsImpl>(std::move(task_runner))} {}
 
-void CMainSignals::RegisterBackgroundSignalScheduler(CScheduler& scheduler)
+ValidationSignals::~ValidationSignals() {}
+
+void ValidationSignals::FlushBackgroundCallbacks()
 {
-    assert(!m_internals);
-    m_internals = std::make_unique<MainSignalsImpl>(scheduler);
+    m_internals->m_task_runner->flush();
 }
 
-void CMainSignals::UnregisterBackgroundSignalScheduler()
+size_t ValidationSignals::CallbacksPending()
 {
-    m_internals.reset(nullptr);
+    return m_internals->m_task_runner->size();
 }
 
-void CMainSignals::FlushBackgroundCallbacks()
-{
-    if (m_internals) {
-        m_internals->m_schedulerClient.EmptyQueue();
-    }
-}
-
-size_t CMainSignals::CallbacksPending()
-{
-    if (!m_internals) return 0;
-    return m_internals->m_schedulerClient.CallbacksPending();
-}
-
-CMainSignals& GetMainSignals()
-{
-    return g_signals;
-}
-
-void RegisterSharedValidationInterface(std::shared_ptr<CValidationInterface> callbacks)
+void ValidationSignals::RegisterSharedValidationInterface(std::shared_ptr<CValidationInterface> callbacks)
 {
     // Each connection captures the shared_ptr to ensure that each callback is
     // executed before the subscriber is destroyed. For more details see #18338.
-    g_signals.m_internals->Register(std::move(callbacks));
+    m_internals->Register(std::move(callbacks));
 }
 
-void RegisterValidationInterface(CValidationInterface* callbacks)
+void ValidationSignals::RegisterValidationInterface(CValidationInterface* callbacks)
 {
     // Create a shared_ptr with a no-op deleter - CValidationInterface lifecycle
     // is managed by the caller.
     RegisterSharedValidationInterface({callbacks, [](CValidationInterface*){}});
 }
 
-void UnregisterSharedValidationInterface(std::shared_ptr<CValidationInterface> callbacks)
+void ValidationSignals::UnregisterSharedValidationInterface(std::shared_ptr<CValidationInterface> callbacks)
 {
     UnregisterValidationInterface(callbacks.get());
 }
 
-void UnregisterValidationInterface(CValidationInterface* callbacks)
+void ValidationSignals::UnregisterValidationInterface(CValidationInterface* callbacks)
 {
-    if (g_signals.m_internals) {
-        g_signals.m_internals->Unregister(callbacks);
-    }
+    m_internals->Unregister(callbacks);
 }
 
-void UnregisterAllValidationInterfaces()
+void ValidationSignals::UnregisterAllValidationInterfaces()
 {
-    if (!g_signals.m_internals) {
-        return;
-    }
-    g_signals.m_internals->Clear();
+    m_internals->Clear();
 }
 
-void CallFunctionInValidationInterfaceQueue(std::function<void()> func)
+void ValidationSignals::CallFunctionInValidationInterfaceQueue(std::function<void()> func)
 {
-    g_signals.m_internals->m_schedulerClient.AddToProcessQueue(std::move(func));
+    m_internals->m_task_runner->insert(std::move(func));
 }
 
-void SyncWithValidationInterfaceQueue()
+void ValidationSignals::SyncWithValidationInterfaceQueue()
 {
     AssertLockNotHeld(cs_main);
     // Block until the validation queue drains
@@ -183,7 +160,7 @@ void SyncWithValidationInterfaceQueue()
     do {                                                       \
         auto local_name = (name);                              \
         LOG_EVENT("Enqueuing " fmt, local_name, __VA_ARGS__);  \
-        m_internals->m_schedulerClient.AddToProcessQueue([=] { \
+        m_internals->m_task_runner->insert([=] { \
             LOG_EVENT(fmt, local_name, __VA_ARGS__);           \
             event();                                           \
         });                                                    \
@@ -192,7 +169,7 @@ void SyncWithValidationInterfaceQueue()
 #define LOG_EVENT(fmt, ...) \
     LogPrint(BCLog::VALIDATION, fmt "\n", __VA_ARGS__)
 
-void CMainSignals::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) {
+void ValidationSignals::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) {
     // Dependencies exist that require UpdatedBlockTip events to be delivered in the order in which
     // the chain actually updates. One way to ensure this is for the caller to invoke this signal
     // in the same critical section where the chain is updated
@@ -206,7 +183,7 @@ void CMainSignals::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockInd
                           fInitialDownload);
 }
 
-void CMainSignals::TransactionAddedToMempool(const NewMempoolTransactionInfo& tx, uint64_t mempool_sequence)
+void ValidationSignals::TransactionAddedToMempool(const NewMempoolTransactionInfo& tx, uint64_t mempool_sequence)
 {
     auto event = [tx, mempool_sequence, this] {
         m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.TransactionAddedToMempool(tx, mempool_sequence); });
@@ -216,7 +193,7 @@ void CMainSignals::TransactionAddedToMempool(const NewMempoolTransactionInfo& tx
                           tx.info.m_tx->GetWitnessHash().ToString());
 }
 
-void CMainSignals::TransactionRemovedFromMempool(const CTransactionRef& tx, MemPoolRemovalReason reason, uint64_t mempool_sequence) {
+void ValidationSignals::TransactionRemovedFromMempool(const CTransactionRef& tx, MemPoolRemovalReason reason, uint64_t mempool_sequence) {
     auto event = [tx, reason, mempool_sequence, this] {
         m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.TransactionRemovedFromMempool(tx, reason, mempool_sequence); });
     };
@@ -226,7 +203,7 @@ void CMainSignals::TransactionRemovedFromMempool(const CTransactionRef& tx, MemP
                           RemovalReasonToString(reason));
 }
 
-void CMainSignals::BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex) {
+void ValidationSignals::BlockConnected(ChainstateRole role, const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex) {
     auto event = [role, pblock, pindex, this] {
         m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.BlockConnected(role, pblock, pindex); });
     };
@@ -235,7 +212,7 @@ void CMainSignals::BlockConnected(ChainstateRole role, const std::shared_ptr<con
                           pindex->nHeight);
 }
 
-void CMainSignals::MempoolTransactionsRemovedForBlock(const std::vector<RemovedMempoolTransactionInfo>& txs_removed_for_block, unsigned int nBlockHeight)
+void ValidationSignals::MempoolTransactionsRemovedForBlock(const std::vector<RemovedMempoolTransactionInfo>& txs_removed_for_block, unsigned int nBlockHeight)
 {
     auto event = [txs_removed_for_block, nBlockHeight, this] {
         m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.MempoolTransactionsRemovedForBlock(txs_removed_for_block, nBlockHeight); });
@@ -245,7 +222,7 @@ void CMainSignals::MempoolTransactionsRemovedForBlock(const std::vector<RemovedM
                           txs_removed_for_block.size());
 }
 
-void CMainSignals::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex)
+void ValidationSignals::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex)
 {
     auto event = [pblock, pindex, this] {
         m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.BlockDisconnected(pblock, pindex); });
@@ -255,7 +232,7 @@ void CMainSignals::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock
                           pindex->nHeight);
 }
 
-void CMainSignals::ChainStateFlushed(ChainstateRole role, const CBlockLocator &locator) {
+void ValidationSignals::ChainStateFlushed(ChainstateRole role, const CBlockLocator &locator) {
     auto event = [role, locator, this] {
         m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.ChainStateFlushed(role, locator); });
     };
@@ -263,13 +240,13 @@ void CMainSignals::ChainStateFlushed(ChainstateRole role, const CBlockLocator &l
                           locator.IsNull() ? "null" : locator.vHave.front().ToString());
 }
 
-void CMainSignals::BlockChecked(const CBlock& block, const BlockValidationState& state) {
+void ValidationSignals::BlockChecked(const CBlock& block, const BlockValidationState& state) {
     LOG_EVENT("%s: block hash=%s state=%s", __func__,
               block.GetHash().ToString(), state.ToString());
     m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.BlockChecked(block, state); });
 }
 
-void CMainSignals::NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock> &block) {
+void ValidationSignals::NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock> &block) {
     LOG_EVENT("%s: block hash=%s", __func__, block->GetHash().ToString());
     m_internals->Iterate([&](CValidationInterface& callbacks) { callbacks.NewPoWValidBlock(pindex, block); });
 }
diff --git a/src/validationinterface.h b/src/validationinterface.h
index d9292ae2c96..6f49a73c93c 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -6,61 +6,29 @@
 #ifndef BITCOIN_VALIDATIONINTERFACE_H
 #define BITCOIN_VALIDATIONINTERFACE_H
 
-#include <kernel/cs_main.h>
 #include <kernel/chain.h>
+#include <kernel/cs_main.h>
 #include <primitives/transaction.h> // CTransaction(Ref)
 #include <sync.h>
 
+#include <cstddef>
+#include <cstdint>
 #include <functional>
 #include <memory>
+#include <vector>
+
+namespace util {
+class TaskRunnerInterface;
+} // namespace util
 
 class BlockValidationState;
 class CBlock;
 class CBlockIndex;
 struct CBlockLocator;
-class CValidationInterface;
-class CScheduler;
 enum class MemPoolRemovalReason;
 struct RemovedMempoolTransactionInfo;
 struct NewMempoolTransactionInfo;
 
-/** Register subscriber */
-void RegisterValidationInterface(CValidationInterface* callbacks);
-/** Unregister subscriber. DEPRECATED. This is not safe to use when the RPC server or main message handler thread is running. */
-void UnregisterValidationInterface(CValidationInterface* callbacks);
-/** Unregister all subscribers */
-void UnregisterAllValidationInterfaces();
-
-// Alternate registration functions that release a shared_ptr after the last
-// notification is sent. These are useful for race-free cleanup, since
-// unregistration is nonblocking and can return before the last notification is
-// processed.
-/** Register subscriber */
-void RegisterSharedValidationInterface(std::shared_ptr<CValidationInterface> callbacks);
-/** Unregister subscriber */
-void UnregisterSharedValidationInterface(std::shared_ptr<CValidationInterface> callbacks);
-
-/**
- * Pushes a function to callback onto the notification queue, guaranteeing any
- * callbacks generated prior to now are finished when the function is called.
- *
- * Be very careful blocking on func to be called if any locks are held -
- * validation interface clients may not be able to make progress as they often
- * wait for things like cs_main, so blocking until func is called with cs_main
- * will result in a deadlock (that DEBUG_LOCKORDER will miss).
- */
-void CallFunctionInValidationInterfaceQueue(std::function<void ()> func);
-/**
- * This is a synonym for the following, which asserts certain locks are not
- * held:
- *     std::promise<void> promise;
- *     CallFunctionInValidationInterfaceQueue([&promise] {
- *         promise.set_value();
- *     });
- *     promise.get_future().wait();
- */
-void SyncWithValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main);
-
 /**
  * Implement this to subscribe to events generated in validation and mempool
  *
@@ -185,30 +153,65 @@ protected:
      * has been received and connected to the headers tree, though not validated yet.
      */
     virtual void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& block) {};
-    friend class CMainSignals;
+    friend class ValidationSignals;
     friend class ValidationInterfaceTest;
 };
 
-class MainSignalsImpl;
-class CMainSignals {
+class ValidationSignalsImpl;
+class ValidationSignals {
 private:
-    std::unique_ptr<MainSignalsImpl> m_internals;
-
-    friend void ::RegisterSharedValidationInterface(std::shared_ptr<CValidationInterface>);
-    friend void ::UnregisterValidationInterface(CValidationInterface*);
-    friend void ::UnregisterAllValidationInterfaces();
-    friend void ::CallFunctionInValidationInterfaceQueue(std::function<void ()> func);
+    std::unique_ptr<ValidationSignalsImpl> m_internals;
 
 public:
-    /** Register a CScheduler to give callbacks which should run in the background (may only be called once) */
-    void RegisterBackgroundSignalScheduler(CScheduler& scheduler);
-    /** Unregister a CScheduler to give callbacks which should run in the background - these callbacks will now be dropped! */
-    void UnregisterBackgroundSignalScheduler();
+    // The task runner will block validation if it calls its insert method's
+    // func argument synchronously. In this class func contains a loop that
+    // dispatches a single validation event to all subscribers sequentially.
+    explicit ValidationSignals(std::unique_ptr<util::TaskRunnerInterface> task_runner);
+
+    ~ValidationSignals();
+
     /** Call any remaining callbacks on the calling thread */
     void FlushBackgroundCallbacks();
 
     size_t CallbacksPending();
 
+    /** Register subscriber */
+    void RegisterValidationInterface(CValidationInterface* callbacks);
+    /** Unregister subscriber. DEPRECATED. This is not safe to use when the RPC server or main message handler thread is running. */
+    void UnregisterValidationInterface(CValidationInterface* callbacks);
+    /** Unregister all subscribers */
+    void UnregisterAllValidationInterfaces();
+
+    // Alternate registration functions that release a shared_ptr after the last
+    // notification is sent. These are useful for race-free cleanup, since
+    // unregistration is nonblocking and can return before the last notification is
+    // processed.
+    /** Register subscriber */
+    void RegisterSharedValidationInterface(std::shared_ptr<CValidationInterface> callbacks);
+    /** Unregister subscriber */
+    void UnregisterSharedValidationInterface(std::shared_ptr<CValidationInterface> callbacks);
+
+    /**
+     * Pushes a function to callback onto the notification queue, guaranteeing any
+     * callbacks generated prior to now are finished when the function is called.
+     *
+     * Be very careful blocking on func to be called if any locks are held -
+     * validation interface clients may not be able to make progress as they often
+     * wait for things like cs_main, so blocking until func is called with cs_main
+     * will result in a deadlock (that DEBUG_LOCKORDER will miss).
+     */
+    void CallFunctionInValidationInterfaceQueue(std::function<void ()> func);
+
+    /**
+     * This is a synonym for the following, which asserts certain locks are not
+     * held:
+     *     std::promise<void> promise;
+     *     CallFunctionInValidationInterfaceQueue([&promise] {
+     *         promise.set_value();
+     *     });
+     *     promise.get_future().wait();
+     */
+    void SyncWithValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main);
 
     void UpdatedBlockTip(const CBlockIndex *, const CBlockIndex *, bool fInitialDownload);
     void TransactionAddedToMempool(const NewMempoolTransactionInfo&, uint64_t mempool_sequence);
@@ -221,6 +224,4 @@ public:
     void NewPoWValidBlock(const CBlockIndex *, const std::shared_ptr<const CBlock>&);
 };
 
-CMainSignals& GetMainSignals();
-
 #endif // BITCOIN_VALIDATIONINTERFACE_H
diff --git a/src/wallet/test/util.cpp b/src/wallet/test/util.cpp
index cbf3ccd1ec1..49d206f4090 100644
--- a/src/wallet/test/util.cpp
+++ b/src/wallet/test/util.cpp
@@ -71,7 +71,8 @@ std::shared_ptr<CWallet> TestLoadWallet(WalletContext& context)
 
 void TestUnloadWallet(std::shared_ptr<CWallet>&& wallet)
 {
-    SyncWithValidationInterfaceQueue();
+    // Calls SyncWithValidationInterfaceQueue
+    wallet->chain().waitForNotificationsIfTipChanged({});
     wallet->m_chain_notifications_handler.reset();
     UnloadWallet(std::move(wallet));
 }
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 27a81b36691..3a67b9a4333 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -814,7 +814,7 @@ BOOST_FIXTURE_TEST_CASE(CreateWallet, TestChain100Setup)
     // transactionAddedToMempool notifications, and create block and mempool
     // transactions paying to the wallet
     std::promise<void> promise;
-    CallFunctionInValidationInterfaceQueue([&promise] {
+    m_node.validation_signals->CallFunctionInValidationInterfaceQueue([&promise] {
         promise.get_future().wait();
     });
     std::string error;
@@ -842,7 +842,7 @@ BOOST_FIXTURE_TEST_CASE(CreateWallet, TestChain100Setup)
     // Unblock notification queue and make sure stale blockConnected and
     // transactionAddedToMempool events are processed
     promise.set_value();
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
     // AddToWallet events for block_tx and mempool_tx events are counted a
     // second time as the notification queue is processed
     BOOST_CHECK_EQUAL(addtx_count, 5);
@@ -865,7 +865,7 @@ BOOST_FIXTURE_TEST_CASE(CreateWallet, TestChain100Setup)
             m_coinbase_txns.push_back(CreateAndProcessBlock({block_tx}, GetScriptForRawPubKey(coinbaseKey.GetPubKey())).vtx[0]);
             mempool_tx = TestSimpleSpend(*m_coinbase_txns[3], 0, coinbaseKey, GetScriptForRawPubKey(key.GetPubKey()));
             BOOST_CHECK(m_node.chain->broadcastTransaction(MakeTransactionRef(mempool_tx), DEFAULT_TRANSACTION_MAXFEE, false, error));
-            SyncWithValidationInterfaceQueue();
+            m_node.validation_signals->SyncWithValidationInterfaceQueue();
         });
     wallet = TestLoadWallet(context);
     // Since mempool transactions are requested at the end of loading, there will
@@ -905,7 +905,7 @@ BOOST_FIXTURE_TEST_CASE(RemoveTxs, TestChain100Setup)
     auto block_tx = TestSimpleSpend(*m_coinbase_txns[0], 0, coinbaseKey, GetScriptForRawPubKey(key.GetPubKey()));
     CreateAndProcessBlock({block_tx}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
 
-    SyncWithValidationInterfaceQueue();
+    m_node.validation_signals->SyncWithValidationInterfaceQueue();
 
     {
         auto block_hash = block_tx.GetHash();