diff --git a/pkg/core/mempool/mem_pool.go b/pkg/core/mempool/mem_pool.go
index d393f6e34..d01962ef0 100644
--- a/pkg/core/mempool/mem_pool.go
+++ b/pkg/core/mempool/mem_pool.go
@@ -10,6 +10,7 @@ import (
 	"github.com/holiman/uint256"
 	"github.com/nspcc-dev/neo-go/pkg/core/mempoolevent"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/network/payload"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"go.uber.org/atomic"
 )
@@ -289,7 +290,13 @@ func (mp *Pool) Add(t *transaction.Transaction, fee Feer, data ...interface{}) e
 	updateMempoolMetrics(len(mp.verifiedTxes))
 	mp.lock.Unlock()
 
+	if pItem.data != nil {
+		r := pItem.data.(*payload.P2PNotaryRequest)
+		fmt.Printf("Mempool: notary request added:\n\tmain hash: %s\n\tfb hash: %s\n\tVUB: %d\n", r.MainTransaction.Hash(), r.FallbackTransaction.Hash(), r.MainTransaction.ValidUntilBlock)
+	}
+
 	if mp.subscriptionsOn.Load() {
+		fmt.Println("Mempool: event sent to events")
 		mp.events <- mempoolevent.Event{
 			Type: mempoolevent.TransactionAdded,
 			Tx:   pItem.txn,
diff --git a/pkg/core/mempool/subscriptions.go b/pkg/core/mempool/subscriptions.go
index 0188c1994..174c35f84 100644
--- a/pkg/core/mempool/subscriptions.go
+++ b/pkg/core/mempool/subscriptions.go
@@ -1,6 +1,10 @@
 package mempool
 
-import "github.com/nspcc-dev/neo-go/pkg/core/mempoolevent"
+import (
+	"errors"
+
+	"github.com/nspcc-dev/neo-go/pkg/core/mempoolevent"
+)
 
 // RunSubscriptions runs subscriptions goroutine if mempool subscriptions are enabled.
 // You should manually free the resources by calling StopSubscriptions on mempool shutdown.
@@ -29,10 +33,12 @@ func (mp *Pool) StopSubscriptions() {
 // there is a new transactions added to the mempool or an existing transaction removed from
 // the mempool, you'll receive it via this channel. Make sure you're not changing the received
 // mempool events, as it may affect the functionality of other subscribers.
-func (mp *Pool) SubscribeForTransactions(ch chan<- mempoolevent.Event) {
+func (mp *Pool) SubscribeForTransactions(ch chan<- mempoolevent.Event) error {
 	if mp.subscriptionsOn.Load() {
 		mp.subCh <- ch
+		return nil
 	}
+	return errors.New("mempool subscriptions are disabled")
 }
 
 // UnsubscribeFromTransactions unsubscribes the given channel from new mempool notifications,
diff --git a/pkg/core/mempool/subscriptions_test.go b/pkg/core/mempool/subscriptions_test.go
index bbe1bc2a3..5ff402047 100644
--- a/pkg/core/mempool/subscriptions_test.go
+++ b/pkg/core/mempool/subscriptions_test.go
@@ -28,7 +28,7 @@ func TestSubscriptions(t *testing.T) {
 		mp.RunSubscriptions()
 		subChan1 := make(chan mempoolevent.Event, 3)
 		subChan2 := make(chan mempoolevent.Event, 3)
-		mp.SubscribeForTransactions(subChan1)
+		_ = mp.SubscribeForTransactions(subChan1)
 		t.Cleanup(mp.StopSubscriptions)
 
 		txs := make([]*transaction.Transaction, 4)
@@ -46,7 +46,7 @@ func TestSubscriptions(t *testing.T) {
 		require.Equal(t, mempoolevent.Event{Type: mempoolevent.TransactionAdded, Tx: txs[0]}, event)
 
 		// severak subscribers
-		mp.SubscribeForTransactions(subChan2)
+		_ = mp.SubscribeForTransactions(subChan2)
 		require.NoError(t, mp.Add(txs[1], fs))
 		require.Eventually(t, func() bool { return len(subChan1) == 1 && len(subChan2) == 1 }, time.Second, time.Millisecond*100)
 		event1 := <-subChan1
diff --git a/pkg/network/server.go b/pkg/network/server.go
index ca37d774f..405cbab5c 100644
--- a/pkg/network/server.go
+++ b/pkg/network/server.go
@@ -544,6 +544,7 @@ func (s *Server) tryStartServices() {
 	if s.IsInSync() && s.syncReached.CAS(false, true) {
 		s.log.Info("node reached synchronized state, starting services")
 		if s.chain.P2PSigExtensionsEnabled() {
+			s.log.Info("starting notary request pool subscriptions")
 			s.notaryRequestPool.RunSubscriptions() // WSClient is also a subscriber.
 		}
 		s.serviceLock.RLock()
@@ -561,11 +562,11 @@ func (s *Server) tryStartServices() {
 // other Server functions. Make sure you're not changing the received mempool
 // events, as it may affect the functionality of Blockchain and other subscribers.
 // Ensure that P2PSigExtensions are enabled before calling this method.
-func (s *Server) SubscribeForNotaryRequests(ch chan<- mempoolevent.Event) {
+func (s *Server) SubscribeForNotaryRequests(ch chan<- mempoolevent.Event) error {
 	if !s.chain.P2PSigExtensionsEnabled() {
 		panic("P2PSigExtensions are disabled")
 	}
-	s.notaryRequestPool.SubscribeForTransactions(ch)
+	return s.notaryRequestPool.SubscribeForTransactions(ch)
 }
 
 // UnsubscribeFromNotaryRequests unsubscribes the given channel from notary request
diff --git a/pkg/services/notary/notary.go b/pkg/services/notary/notary.go
index e3b6bea96..2cebca5e0 100644
--- a/pkg/services/notary/notary.go
+++ b/pkg/services/notary/notary.go
@@ -176,7 +176,12 @@ func (n *Notary) Start() {
 	}
 	n.Config.Log.Info("starting notary service")
 	n.Config.Chain.SubscribeForBlocks(n.blocksCh)
-	n.mp.SubscribeForTransactions(n.reqCh)
+	// TODO: we need to be strictly sure that mempool subscriptions are properly enabled by
+	// the moment Notary service is starting
+	err := n.mp.SubscribeForTransactions(n.reqCh)
+	if err != nil {
+		n.Config.Log.Fatal("failed to subscribe for notary requests", zap.Error(err))
+	}
 	go n.newTxCallbackLoop()
 	go n.mainLoop()
 }
diff --git a/pkg/services/rpcsrv/client_test.go b/pkg/services/rpcsrv/client_test.go
index 031dab5ee..5516ff3b1 100644
--- a/pkg/services/rpcsrv/client_test.go
+++ b/pkg/services/rpcsrv/client_test.go
@@ -3,6 +3,7 @@ package rpcsrv
 import (
 	"bytes"
 	"context"
+	"crypto/elliptic"
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
@@ -52,6 +53,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
 	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/vm"
 	"github.com/nspcc-dev/neo-go/pkg/vm/emit"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
@@ -61,6 +63,130 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func getCosigners(t *testing.T, multisig *wallet.Account, acc *wallet.Account, rubles util.Uint160) []actor.SignerAccount {
+	ss := make([]actor.SignerAccount, 0, 3)
+
+	m, pubsB, ok := vm.ParseMultiSigContract(multisig.Contract.Script)
+	require.True(t, ok)
+	pubs := make(keys.PublicKeys, len(pubsB))
+	var err error
+	for i := range pubsB {
+		pubs[i], err = keys.NewPublicKeyFromBytes(pubsB[i], elliptic.P256())
+		require.NoError(t, err)
+	}
+	fakeMultisig, err := notary.FakeMultisigAccount(m, pubs)
+	require.NoError(t, err)
+
+	ss = append(ss, []actor.SignerAccount{
+		{
+			// proxy contract
+			Signer: transaction.Signer{
+				Account: rubles,
+				Scopes:  transaction.None,
+			},
+			Account: notary.FakeContractAccount(rubles),
+		},
+		{
+			// multi signature (committee, in fact)
+			Signer: transaction.Signer{
+				Account: multisig.ScriptHash(),
+				Scopes:  transaction.Global,
+			},
+			Account: fakeMultisig, // encrypted
+		},
+	}...)
+
+	// invoker signature
+	ss = append(ss, actor.SignerAccount{
+		Signer: transaction.Signer{
+			Account: hash.Hash160(acc.GetVerificationScript()),
+			Scopes:  transaction.Global,
+		},
+		Account: acc,
+	})
+	return ss
+}
+
+func TestNotarizator(t *testing.T) {
+	c, err := rpcclient.NewWS(context.Background(), "ws://localhost:20331/ws", rpcclient.Options{})
+	require.NoError(t, err)
+	require.NoError(t, c.Init())
+
+	w, err := wallet.NewWalletFromFile("../../../.docker/wallets/wallet1.json")
+	require.NoError(t, err)
+	acc := w.Accounts[0]
+	require.NoError(t, acc.Decrypt("one", w.Scrypt))
+
+	rubles, err := util.Uint160DecodeStringLE(testContractHash)
+	require.NoError(t, err)
+
+	multisig := w.Accounts[1]
+	cosigners := getCosigners(t, multisig, acc, rubles)
+
+	nAct, err := notary.NewActor(c, cosigners, acc)
+	require.NoError(t, err)
+
+	fmt.Println("actor created, starting subscriptions")
+	go subsLoop(t, rubles)
+
+	time.Sleep(10 * time.Second)
+
+	fmt.Println("starting notarizator")
+	mainH, fbHash, VUB, err := nAct.Notarize(nAct.MakeTunedCall(rubles, "putValue", nil, func(r *result.Invoke, t *transaction.Transaction) error {
+		if r.State != vmstate.Halt.String() {
+			return fmt.Errorf("FAULT putValue call: %s", r.FaultException)
+		}
+
+		t.ValidUntilBlock = 64
+		t.Nonce = 4
+
+		return nil
+	}, "notarykey", "notaryvalue"))
+
+	fmt.Printf("Notary request sent:\n\tmain hash: %s\n\tfb hash: %s\n\tVUB: %d\n\terr: %v\n\n", mainH.StringLE(), fbHash.StringLE(), VUB, err)
+
+	time.Sleep(20 * time.Second)
+}
+
+func subsLoop(t *testing.T, rubles util.Uint160) {
+	c, err := rpcclient.NewWS(context.Background(), "ws://localhost:20331/ws", rpcclient.Options{})
+	require.NoError(t, err)
+	require.NoError(t, c.Init())
+	ch := c.Notifications
+	exitCh := make(chan struct{})
+	go func() {
+	subsLoop:
+		for {
+			select {
+			case r, ok := <-ch:
+				if !ok {
+					fmt.Println("Subscriptions listener: !ok")
+					break subsLoop
+				}
+				switch r.Type {
+				case neorpc.NotaryRequestEventID:
+					val := r.Value.(*result.NotaryRequestEvent)
+					fmt.Printf("Notary request event:\n\ttype: %s\n\tmain hash: %s\n\tfb hash: %s\n\n", val.Type, val.NotaryRequest.MainTransaction.Hash().StringLE(), val.NotaryRequest.FallbackTransaction.Hash().StringLE())
+				default:
+					fmt.Printf("Non-notary event: %s\n", r.Type)
+				}
+			}
+		}
+
+		for range ch {
+		}
+		exitCh <- struct{}{}
+	}()
+	id, err := c.SubscribeForNotaryRequests(nil, &rubles)
+	require.NoError(t, err)
+	fmt.Println("subscribed for notary requests")
+	<-exitCh
+	close(ch)
+	close(exitCh)
+	require.NoError(t, c.Unsubscribe(id))
+	fmt.Println("unsubscribed from notary requests")
+}
+
 func TestClient_NEP17(t *testing.T) {
 	chain, rpcSrv, httpSrv := initServerWithInMemoryChain(t)
 	defer chain.Close()
diff --git a/pkg/services/rpcsrv/server.go b/pkg/services/rpcsrv/server.go
index 6531ccaf8..e7fdcd384 100644
--- a/pkg/services/rpcsrv/server.go
+++ b/pkg/services/rpcsrv/server.go
@@ -2572,7 +2572,10 @@ func (s *Server) subscribe(reqParams params.Params, sub *subscriber) (interface{
 		return nil, neorpc.NewInternalServerError("server is shutting down")
 	default:
 	}
-	s.subscribeToChannel(event)
+	err = s.subscribeToChannel(event)
+	if err != nil {
+		return nil, neorpc.NewInternalServerError(fmt.Errorf("failed to subscribe: %w", err).Error())
+	}
 	s.subsCounterLock.Unlock()
 	return strconv.FormatInt(int64(id), 10), nil
 }
@@ -2580,7 +2583,7 @@ func (s *Server) subscribe(reqParams params.Params, sub *subscriber) (interface{
 // subscribeToChannel subscribes RPC server to appropriate chain events if
 // it's not yet subscribed for them. It's supposed to be called with s.subsCounterLock
 // taken by the caller.
-func (s *Server) subscribeToChannel(event neorpc.EventID) {
+func (s *Server) subscribeToChannel(event neorpc.EventID) error {
 	switch event {
 	case neorpc.BlockEventID:
 		if s.blockSubs == 0 {
@@ -2604,10 +2607,16 @@ func (s *Server) subscribeToChannel(event neorpc.EventID) {
 		s.executionSubs++
 	case neorpc.NotaryRequestEventID:
 		if s.notaryRequestSubs == 0 {
-			s.coreServer.SubscribeForNotaryRequests(s.notaryRequestCh)
+			s.log.Info("rpc: subscribing for notary request pool")
+			err := s.coreServer.SubscribeForNotaryRequests(s.notaryRequestCh)
+			if err != nil {
+				s.log.Warn("failed to subscribe for notary requests", zap.Error(err))
+				break
+			}
 		}
 		s.notaryRequestSubs++
 	}
+	return nil
 }
 
 // unsubscribe handles unsubscription requests from websocket clients.