diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index e5a7a5519..c47a97283 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -29,7 +29,7 @@ import (
 // Tuning parameters.
 const (
 	headerBatchCount = 2000
-	version          = "0.0.8"
+	version          = "0.0.9"
 
 	// This one comes from C# code and it's different from the constant used
 	// when creating an asset with Neo.Asset.Create interop call. It looks
@@ -708,7 +708,7 @@ func (bc *Blockchain) storeBlock(block *block.Block) error {
 				Trigger:     trigger.Application,
 				VMState:     v.State(),
 				GasConsumed: v.GasConsumed(),
-				Stack:       v.Stack("estack"),
+				Stack:       v.Estack().ToContractParameters(),
 				Events:      systemInterop.notifications,
 			}
 			err = cache.PutAppExecResult(aer)
diff --git a/pkg/core/dao_test.go b/pkg/core/dao_test.go
index 94125ecd7..b49296658 100644
--- a/pkg/core/dao_test.go
+++ b/pkg/core/dao_test.go
@@ -171,7 +171,11 @@ func TestGetValidators(t *testing.T) {
 func TestPutGetAppExecResult(t *testing.T) {
 	dao := newDao(storage.NewMemoryStore())
 	hash := random.Uint256()
-	appExecResult := &state.AppExecResult{TxHash: hash, Events: []state.NotificationEvent{}}
+	appExecResult := &state.AppExecResult{
+		TxHash: hash,
+		Events: []state.NotificationEvent{},
+		Stack:  []smartcontract.Parameter{},
+	}
 	err := dao.PutAppExecResult(appExecResult)
 	require.NoError(t, err)
 	gotAppExecResult, err := dao.GetAppExecResult(hash)
diff --git a/pkg/core/state/notification_event.go b/pkg/core/state/notification_event.go
index 24e6659e8..2599f781e 100644
--- a/pkg/core/state/notification_event.go
+++ b/pkg/core/state/notification_event.go
@@ -2,6 +2,7 @@ package state
 
 import (
 	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"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"
@@ -21,7 +22,7 @@ type AppExecResult struct {
 	Trigger     trigger.Type
 	VMState     string
 	GasConsumed util.Fixed8
-	Stack       string // JSON
+	Stack       []smartcontract.Parameter
 	Events      []NotificationEvent
 }
 
@@ -43,7 +44,7 @@ func (aer *AppExecResult) EncodeBinary(w *io.BinWriter) {
 	w.WriteB(byte(aer.Trigger))
 	w.WriteString(aer.VMState)
 	aer.GasConsumed.EncodeBinary(w)
-	w.WriteString(aer.Stack)
+	w.WriteArray(aer.Stack)
 	w.WriteArray(aer.Events)
 }
 
@@ -53,6 +54,6 @@ func (aer *AppExecResult) DecodeBinary(r *io.BinReader) {
 	aer.Trigger = trigger.Type(r.ReadB())
 	aer.VMState = r.ReadString()
 	aer.GasConsumed.DecodeBinary(r)
-	aer.Stack = r.ReadString()
+	r.ReadArray(&aer.Stack)
 	r.ReadArray(&aer.Events)
 }
diff --git a/pkg/core/state/notification_event_test.go b/pkg/core/state/notification_event_test.go
index 0f28e2957..3deb48845 100644
--- a/pkg/core/state/notification_event_test.go
+++ b/pkg/core/state/notification_event_test.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/nspcc-dev/neo-go/pkg/internal/random"
 	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -30,7 +31,7 @@ func TestEncodeDecodeAppExecResult(t *testing.T) {
 		Trigger:     1,
 		VMState:     "Hault",
 		GasConsumed: 10,
-		Stack:       "",
+		Stack:       []smartcontract.Parameter{},
 		Events:      []NotificationEvent{},
 	}
 	buf := io.NewBufBinWriter()
diff --git a/pkg/rpc/response/result/application_log.go b/pkg/rpc/response/result/application_log.go
index 27e2026c0..da436f2f4 100644
--- a/pkg/rpc/response/result/application_log.go
+++ b/pkg/rpc/response/result/application_log.go
@@ -1,8 +1,6 @@
 package result
 
 import (
-	"encoding/json"
-
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/util"
@@ -18,12 +16,12 @@ type ApplicationLog struct {
 
 // Execution response wrapper
 type Execution struct {
-	Trigger     string              `json:"trigger"`
-	ScriptHash  util.Uint160        `json:"contract"`
-	VMState     string              `json:"vmstate"`
-	GasConsumed util.Fixed8         `json:"gas_consumed"`
-	Stack       json.RawMessage     `json:"stack"`
-	Events      []NotificationEvent `json:"notifications"`
+	Trigger     string                    `json:"trigger"`
+	ScriptHash  util.Uint160              `json:"contract"`
+	VMState     string                    `json:"vmstate"`
+	GasConsumed util.Fixed8               `json:"gas_consumed"`
+	Stack       []smartcontract.Parameter `json:"stack"`
+	Events      []NotificationEvent       `json:"notifications"`
 }
 
 //NotificationEvent response wrapper
@@ -46,18 +44,12 @@ func NewApplicationLog(appExecRes *state.AppExecResult, scriptHash util.Uint160)
 
 	triggerString := appExecRes.Trigger.String()
 
-	var rawStack json.RawMessage
-	if len(appExecRes.Stack) != 0 {
-		rawStack = json.RawMessage(appExecRes.Stack)
-	} else {
-		rawStack = json.RawMessage("[]")
-	}
 	executions := []Execution{{
 		Trigger:     triggerString,
 		ScriptHash:  scriptHash,
 		VMState:     appExecRes.VMState,
 		GasConsumed: appExecRes.GasConsumed,
-		Stack:       rawStack,
+		Stack:       appExecRes.Stack,
 		Events:      events,
 	}}