diff --git a/pkg/compiler/interop_test.go b/pkg/compiler/interop_test.go
index 165247b03..135f1bc61 100644
--- a/pkg/compiler/interop_test.go
+++ b/pkg/compiler/interop_test.go
@@ -193,7 +193,7 @@ func TestAppCall(t *testing.T) {
 	}
 
 	fc := fakechain.NewFakeChain()
-	ic := interop.NewContext(trigger.Application, fc, dao.NewSimple(storage.NewMemoryStore(), false), contractGetter, nil, nil, nil, zaptest.NewLogger(t))
+	ic := interop.NewContext(trigger.Application, fc, dao.NewSimple(storage.NewMemoryStore(), false, false), contractGetter, nil, nil, nil, zaptest.NewLogger(t))
 
 	t.Run("valid script", func(t *testing.T) {
 		src := getAppCallScript(fmt.Sprintf("%#v", ih.BytesBE()))
diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index eafbad313..0d699e416 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -235,8 +235,8 @@ func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.L
 	}
 	bc := &Blockchain{
 		config:      cfg,
-		dao:         dao.NewSimple(s, cfg.StateRootInHeader),
-		persistent:  dao.NewSimple(s, cfg.StateRootInHeader),
+		dao:         dao.NewSimple(s, cfg.StateRootInHeader, cfg.P2PSigExtensions),
+		persistent:  dao.NewSimple(s, cfg.StateRootInHeader, cfg.P2PSigExtensions),
 		stopCh:      make(chan struct{}),
 		runToExitCh: make(chan struct{}),
 		memPool:     mempool.New(cfg.MemPoolSize, 0, false),
diff --git a/pkg/core/dao/dao.go b/pkg/core/dao/dao.go
index b895d1033..93a0d4a56 100644
--- a/pkg/core/dao/dao.go
+++ b/pkg/core/dao/dao.go
@@ -77,12 +77,14 @@ type Simple struct {
 	Store *storage.MemCachedStore
 	// stateRootInHeader specifies if block header contains state root.
 	stateRootInHeader bool
+	// p2pSigExtensions denotes whether P2PSignatureExtensions are enabled.
+	p2pSigExtensions bool
 }
 
 // NewSimple creates new simple dao using provided backend store.
-func NewSimple(backend storage.Store, stateRootInHeader bool) *Simple {
+func NewSimple(backend storage.Store, stateRootInHeader bool, p2pSigExtensions bool) *Simple {
 	st := storage.NewMemCachedStore(backend)
-	return &Simple{Store: st, stateRootInHeader: stateRootInHeader}
+	return &Simple{Store: st, stateRootInHeader: stateRootInHeader, p2pSigExtensions: p2pSigExtensions}
 }
 
 // GetBatch returns currently accumulated DB changeset.
@@ -93,7 +95,7 @@ func (dao *Simple) GetBatch() *storage.MemBatch {
 // GetWrapped returns new DAO instance with another layer of wrapped
 // MemCachedStore around the current DAO Store.
 func (dao *Simple) GetWrapped() DAO {
-	d := NewSimple(dao.Store, dao.stateRootInHeader)
+	d := NewSimple(dao.Store, dao.stateRootInHeader, dao.p2pSigExtensions)
 	return d
 }
 
@@ -585,6 +587,13 @@ func (dao *Simple) DeleteBlock(h util.Uint256, w *io.BufBinWriter) error {
 	for _, tx := range b.Transactions {
 		copy(key[1:], tx.Hash().BytesBE())
 		batch.Delete(key)
+		if dao.p2pSigExtensions {
+			for _, attr := range tx.GetAttributes(transaction.ConflictsT) {
+				hash := attr.Value.(*transaction.Conflicts).Hash
+				copy(key[1:], hash.BytesBE())
+				batch.Delete(key)
+			}
+		}
 		key[0] = byte(storage.STNotification)
 		batch.Delete(key)
 	}
diff --git a/pkg/core/dao/dao_test.go b/pkg/core/dao/dao_test.go
index 581b0e521..f6caf6993 100644
--- a/pkg/core/dao/dao_test.go
+++ b/pkg/core/dao/dao_test.go
@@ -17,7 +17,7 @@ import (
 )
 
 func TestPutGetAndDecode(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	serializable := &TestSerializable{field: random.String(4)}
 	hash := []byte{1}
 	err := dao.Put(serializable, hash)
@@ -42,7 +42,7 @@ func (t *TestSerializable) DecodeBinary(reader *io.BinReader) {
 }
 
 func TestPutGetAppExecResult(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	hash := random.Uint256()
 	appExecResult := &state.AppExecResult{
 		Container: hash,
@@ -60,7 +60,7 @@ func TestPutGetAppExecResult(t *testing.T) {
 }
 
 func TestPutGetStorageItem(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	id := int32(random.Int(0, 1024))
 	key := []byte{0}
 	storageItem := state.StorageItem{}
@@ -71,7 +71,7 @@ func TestPutGetStorageItem(t *testing.T) {
 }
 
 func TestDeleteStorageItem(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	id := int32(random.Int(0, 1024))
 	key := []byte{0}
 	storageItem := state.StorageItem{}
@@ -84,7 +84,7 @@ func TestDeleteStorageItem(t *testing.T) {
 }
 
 func TestGetBlock_NotExists(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	hash := random.Uint256()
 	block, err := dao.GetBlock(hash)
 	require.Error(t, err)
@@ -92,7 +92,7 @@ func TestGetBlock_NotExists(t *testing.T) {
 }
 
 func TestPutGetBlock(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	b := &block.Block{
 		Header: block.Header{
 			Script: transaction.Witness{
@@ -110,14 +110,14 @@ func TestPutGetBlock(t *testing.T) {
 }
 
 func TestGetVersion_NoVersion(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	version, err := dao.GetVersion()
 	require.Error(t, err)
 	require.Equal(t, "", version)
 }
 
 func TestGetVersion(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	err := dao.PutVersion("testVersion")
 	require.NoError(t, err)
 	version, err := dao.GetVersion()
@@ -126,14 +126,14 @@ func TestGetVersion(t *testing.T) {
 }
 
 func TestGetCurrentHeaderHeight_NoHeader(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	height, err := dao.GetCurrentBlockHeight()
 	require.Error(t, err)
 	require.Equal(t, uint32(0), height)
 }
 
 func TestGetCurrentHeaderHeight_Store(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	b := &block.Block{
 		Header: block.Header{
 			Script: transaction.Witness{
@@ -150,7 +150,7 @@ func TestGetCurrentHeaderHeight_Store(t *testing.T) {
 }
 
 func TestStoreAsTransaction(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), false)
+	dao := NewSimple(storage.NewMemoryStore(), false, false)
 	tx := transaction.New([]byte{byte(opcode.PUSH1)}, 1)
 	hash := tx.Hash()
 	err := dao.StoreAsTransaction(tx, 0, nil)
@@ -173,7 +173,7 @@ func TestMakeStorageItemKey(t *testing.T) {
 }
 
 func TestPutGetStateSyncPoint(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), true)
+	dao := NewSimple(storage.NewMemoryStore(), true, false)
 
 	// empty store
 	_, err := dao.GetStateSyncPoint()
@@ -188,7 +188,7 @@ func TestPutGetStateSyncPoint(t *testing.T) {
 }
 
 func TestPutGetStateSyncCurrentBlockHeight(t *testing.T) {
-	dao := NewSimple(storage.NewMemoryStore(), true)
+	dao := NewSimple(storage.NewMemoryStore(), true, false)
 
 	// empty store
 	_, err := dao.GetStateSyncCurrentBlockHeight()
diff --git a/pkg/core/interop/crypto/ecdsa_test.go b/pkg/core/interop/crypto/ecdsa_test.go
index 0099e35d2..3331d7f25 100644
--- a/pkg/core/interop/crypto/ecdsa_test.go
+++ b/pkg/core/interop/crypto/ecdsa_test.go
@@ -71,7 +71,7 @@ func initCheckMultisigVMNoArgs(container *transaction.Transaction) *vm.VM {
 	ic := interop.NewContext(
 		trigger.Verification,
 		fakechain.NewFakeChain(),
-		dao.NewSimple(storage.NewMemoryStore(), false),
+		dao.NewSimple(storage.NewMemoryStore(), false, false),
 		nil, nil, nil,
 		container,
 		nil)
@@ -177,7 +177,7 @@ func TestCheckSig(t *testing.T) {
 	require.NoError(t, err)
 
 	verifyFunc := ECDSASecp256r1CheckSig
-	d := dao.NewSimple(storage.NewMemoryStore(), false)
+	d := dao.NewSimple(storage.NewMemoryStore(), false, false)
 	ic := &interop.Context{Network: uint32(netmode.UnitTestNet), DAO: d}
 	runCase := func(t *testing.T, isErr bool, result interface{}, args ...interface{}) {
 		ic.SpawnVM()
diff --git a/pkg/core/interop_system_test.go b/pkg/core/interop_system_test.go
index 62e0ab5f6..06d89814f 100644
--- a/pkg/core/interop_system_test.go
+++ b/pkg/core/interop_system_test.go
@@ -552,7 +552,7 @@ func TestStorageFind(t *testing.T) {
 func createVM(t *testing.T) (*vm.VM, *interop.Context, *Blockchain) {
 	chain := newTestChain(t)
 	context := chain.newInteropContext(trigger.Application,
-		dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader), nil, nil)
+		dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader, chain.config.P2PSigExtensions), nil, nil)
 	v := context.SpawnVM()
 	return v, context, chain
 }
@@ -572,7 +572,7 @@ func createVMAndContractState(t testing.TB) (*vm.VM, *state.Contract, *interop.C
 	}
 
 	chain := newTestChain(t)
-	d := dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader)
+	d := dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader, chain.config.P2PSigExtensions)
 	context := chain.newInteropContext(trigger.Application, d, nil, nil)
 	v := context.SpawnVM()
 	return v, contractState, context, chain
@@ -584,7 +584,7 @@ func createVMAndTX(t *testing.T) (*vm.VM, *transaction.Transaction, *interop.Con
 	tx.Signers = []transaction.Signer{{Account: util.Uint160{1, 2, 3, 4}}}
 	tx.Scripts = []transaction.Witness{{InvocationScript: []byte{}, VerificationScript: []byte{}}}
 	chain := newTestChain(t)
-	d := dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader)
+	d := dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader, chain.config.P2PSigExtensions)
 	context := chain.newInteropContext(trigger.Application, d, nil, tx)
 	v := context.SpawnVM()
 	return v, tx, context, chain
diff --git a/pkg/core/interops_test.go b/pkg/core/interops_test.go
index 0db9acd40..ef4dde7bf 100644
--- a/pkg/core/interops_test.go
+++ b/pkg/core/interops_test.go
@@ -17,7 +17,7 @@ func testNonInterop(t *testing.T, value interface{}, f func(*interop.Context) er
 	v := vm.New()
 	v.Estack().PushVal(value)
 	chain := newTestChain(t)
-	d := dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader)
+	d := dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader, chain.config.P2PSigExtensions)
 	context := chain.newInteropContext(trigger.Application, d, nil, nil)
 	context.VM = v
 	require.Error(t, f(context))
diff --git a/pkg/core/native/management_test.go b/pkg/core/native/management_test.go
index 91f72bdf6..b7715e16e 100644
--- a/pkg/core/native/management_test.go
+++ b/pkg/core/native/management_test.go
@@ -17,7 +17,7 @@ import (
 
 func TestDeployGetUpdateDestroyContract(t *testing.T) {
 	mgmt := newManagement()
-	d := dao.NewSimple(storage.NewMemoryStore(), false)
+	d := dao.NewSimple(storage.NewMemoryStore(), false, false)
 	err := mgmt.Initialize(&interop.Context{DAO: d})
 	require.NoError(t, err)
 	script := []byte{byte(opcode.RET)}
@@ -72,12 +72,12 @@ func TestDeployGetUpdateDestroyContract(t *testing.T) {
 
 func TestManagement_Initialize(t *testing.T) {
 	t.Run("good", func(t *testing.T) {
-		d := dao.NewSimple(storage.NewMemoryStore(), false)
+		d := dao.NewSimple(storage.NewMemoryStore(), false, false)
 		mgmt := newManagement()
 		require.NoError(t, mgmt.InitializeCache(d))
 	})
 	t.Run("invalid contract state", func(t *testing.T) {
-		d := dao.NewSimple(storage.NewMemoryStore(), false)
+		d := dao.NewSimple(storage.NewMemoryStore(), false, false)
 		mgmt := newManagement()
 		require.NoError(t, d.PutStorageItem(mgmt.ID, []byte{prefixContract}, state.StorageItem{0xFF}))
 		require.Error(t, mgmt.InitializeCache(d))
@@ -86,7 +86,7 @@ func TestManagement_Initialize(t *testing.T) {
 
 func TestManagement_GetNEP17Contracts(t *testing.T) {
 	mgmt := newManagement()
-	d := dao.NewSimple(storage.NewMemoryStore(), false)
+	d := dao.NewSimple(storage.NewMemoryStore(), false, false)
 	err := mgmt.Initialize(&interop.Context{DAO: d})
 	require.NoError(t, err)
 
diff --git a/pkg/core/native_contract_test.go b/pkg/core/native_contract_test.go
index eb2403b4b..aea370ef4 100644
--- a/pkg/core/native_contract_test.go
+++ b/pkg/core/native_contract_test.go
@@ -227,7 +227,7 @@ func TestNativeContract_InvokeInternal(t *testing.T) {
 	})
 	require.NoError(t, err)
 
-	d := dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader)
+	d := dao.NewSimple(storage.NewMemoryStore(), chain.config.StateRootInHeader, chain.config.P2PSigExtensions)
 	ic := chain.newInteropContext(trigger.Application, d, nil, nil)
 
 	sumOffset := 0