diff --git a/pkg/core/interop/context.go b/pkg/core/interop/context.go
index 1b0f003f8..0160c9b1e 100644
--- a/pkg/core/interop/context.go
+++ b/pkg/core/interop/context.go
@@ -48,14 +48,20 @@ type Context struct {
 	VM            *vm.VM
 	Functions     []Function
 	getContract   func(dao.DAO, util.Uint160) (*state.Contract, error)
+	baseExecFee   int64
 }
 
 // NewContext returns new interop context.
 func NewContext(trigger trigger.Type, bc blockchainer.Blockchainer, d dao.DAO,
 	getContract func(dao.DAO, util.Uint160) (*state.Contract, error), natives []Contract,
 	block *block.Block, tx *transaction.Transaction, log *zap.Logger) *Context {
+	baseExecFee := int64(DefaultBaseExecFee)
 	dao := d.GetWrapped()
 	nes := make([]state.NotificationEvent, 0)
+
+	if bc != nil && (block == nil || block.Index != 0) {
+		baseExecFee = bc.GetPolicer().GetBaseExecFee()
+	}
 	return &Context{
 		Chain:         bc,
 		Network:       uint32(bc.GetConfig().Magic),
@@ -69,6 +75,7 @@ func NewContext(trigger trigger.Type, bc blockchainer.Blockchainer, d dao.DAO,
 		// Functions is a slice of interops sorted by ID.
 		Functions:   []Function{},
 		getContract: getContract,
+		baseExecFee: baseExecFee,
 	}
 }
 
@@ -254,10 +261,7 @@ func (ic *Context) GetFunction(id uint32) *Function {
 
 // BaseExecFee represents factor to multiply syscall prices with.
 func (ic *Context) BaseExecFee() int64 {
-	if ic.Chain == nil || (ic.Block != nil && ic.Block.Index == 0) {
-		return DefaultBaseExecFee
-	}
-	return ic.Chain.GetPolicer().GetBaseExecFee()
+	return ic.baseExecFee
 }
 
 // SyscallHandler handles syscall with id.
diff --git a/pkg/core/interop/crypto/ecdsa_test.go b/pkg/core/interop/crypto/ecdsa_test.go
index c5ca3ab32..a5b39d21a 100644
--- a/pkg/core/interop/crypto/ecdsa_test.go
+++ b/pkg/core/interop/crypto/ecdsa_test.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/nspcc-dev/neo-go/internal/fakechain"
 	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
 	"github.com/nspcc-dev/neo-go/pkg/core/fee"
@@ -67,12 +68,15 @@ func initCheckMultisigVMNoArgs(container *transaction.Transaction) *vm.VM {
 	buf[0] = byte(opcode.SYSCALL)
 	binary.LittleEndian.PutUint32(buf[1:], neoCryptoCheckMultisigID)
 
-	ic := &interop.Context{
-		Network:   uint32(netmode.UnitTestNet),
-		Trigger:   trigger.Verification,
-		Container: container,
-		Functions: Interops,
-	}
+	ic := interop.NewContext(
+		trigger.Verification,
+		fakechain.NewFakeChain(),
+		dao.NewSimple(storage.NewMemoryStore(), false),
+		nil, nil, nil,
+		container,
+		nil)
+	ic.Container = container
+	ic.Functions = Interops
 	v := ic.SpawnVM()
 	v.LoadScript(buf)
 	return v
diff --git a/pkg/core/interop/gas_price.go b/pkg/core/interop/gas_price.go
index c72671411..342dd9e7a 100644
--- a/pkg/core/interop/gas_price.go
+++ b/pkg/core/interop/gas_price.go
@@ -7,5 +7,5 @@ import (
 
 // GetPrice returns a price for executing op with the provided parameter.
 func (ic *Context) GetPrice(op opcode.Opcode, parameter []byte) int64 {
-	return fee.Opcode(ic.BaseExecFee(), op)
+	return fee.Opcode(ic.baseExecFee, op)
 }
diff --git a/pkg/vm/slot.go b/pkg/vm/slot.go
index 22e4d8d5c..75601b309 100644
--- a/pkg/vm/slot.go
+++ b/pkg/vm/slot.go
@@ -26,7 +26,7 @@ func (s *Slot) init(n int) {
 }
 
 func (v *VM) newSlot(n int) *Slot {
-	s := newSlot(v.refs)
+	s := newSlot(&v.refs)
 	s.init(n)
 	return s
 }
diff --git a/pkg/vm/stack.go b/pkg/vm/stack.go
index fca28215b..659ff0191 100644
--- a/pkg/vm/stack.go
+++ b/pkg/vm/stack.go
@@ -162,13 +162,15 @@ func NewStack(n string) *Stack {
 }
 
 func newStack(n string, refc *refCounter) *Stack {
-	s := &Stack{
-		name: n,
-		refs: refc,
-	}
+	s := new(Stack)
+	initStack(s, n, refc)
+	return s
+}
+func initStack(s *Stack, n string, refc *refCounter) {
+	s.name = n
+	s.refs = refc
 	s.top.next = &s.top
 	s.top.prev = &s.top
-	return s
 }
 
 // Clear clears all elements on the stack and set its length to 0.
diff --git a/pkg/vm/vm.go b/pkg/vm/vm.go
index be47455a7..4856270e4 100644
--- a/pkg/vm/vm.go
+++ b/pkg/vm/vm.go
@@ -68,12 +68,12 @@ type VM struct {
 	// callback to get interop price
 	getPrice func(opcode.Opcode, []byte) int64
 
-	istack *Stack // invocation stack.
+	istack Stack  // invocation stack.
 	estack *Stack // execution stack.
 
 	uncaughtException stackitem.Item // exception being handled
 
-	refs *refCounter
+	refs refCounter
 
 	gasConsumed int64
 	GasLimit    int64
@@ -99,15 +99,15 @@ func New() *VM {
 func NewWithTrigger(t trigger.Type) *VM {
 	vm := &VM{
 		state:   NoneState,
-		istack:  newStack("invocation", nil),
-		refs:    newRefCounter(),
 		trigger: t,
 
 		SyscallHandler: defaultSyscallHandler,
 		Invocations:    make(map[util.Uint160]int),
 	}
 
-	vm.estack = newStack("evaluation", vm.refs)
+	vm.refs.items = make(map[stackitem.Item]int)
+	initStack(&vm.istack, "invocation", nil)
+	vm.estack = newStack("evaluation", &vm.refs)
 	return vm
 }
 
@@ -135,7 +135,7 @@ func (v *VM) Estack() *Stack {
 
 // Istack returns the invocation stack so interop hooks can utilize this.
 func (v *VM) Istack() *Stack {
-	return v.istack
+	return &v.istack
 }
 
 // LoadArgs loads in the arguments used in the Mian entry point.
@@ -281,11 +281,11 @@ func (v *VM) LoadScript(b []byte) {
 func (v *VM) LoadScriptWithFlags(b []byte, f callflag.CallFlag) {
 	v.checkInvocationStackSize()
 	ctx := NewContextWithParams(b, 0, -1, 0)
-	v.estack = newStack("evaluation", v.refs)
+	v.estack = newStack("evaluation", &v.refs)
 	ctx.estack = v.estack
 	ctx.tryStack = newStack("exception", nil)
 	ctx.callFlag = f
-	ctx.static = newSlot(v.refs)
+	ctx.static = newSlot(&v.refs)
 	ctx.callingScriptHash = v.GetCurrentScriptHash()
 	v.istack.PushVal(ctx)
 }
@@ -340,7 +340,7 @@ func (v *VM) PopResult() interface{} {
 func (v *VM) Stack(n string) string {
 	var s *Stack
 	if n == "istack" {
-		s = v.istack
+		s = &v.istack
 	}
 	if n == "estack" {
 		s = v.estack
@@ -1786,7 +1786,7 @@ func (v *VM) GetCallingScriptHash() util.Uint160 {
 
 // GetEntryScriptHash implements ScriptHashGetter interface.
 func (v *VM) GetEntryScriptHash() util.Uint160 {
-	return v.getContextScriptHash(v.Istack().Len() - 1)
+	return v.getContextScriptHash(v.istack.len - 1)
 }
 
 // GetCurrentScriptHash implements ScriptHashGetter interface.