diff --git a/pkg/vm/stack_item.go b/pkg/vm/stack_item.go
index 19c5ea6e3..b6ed046a4 100644
--- a/pkg/vm/stack_item.go
+++ b/pkg/vm/stack_item.go
@@ -341,9 +341,7 @@ func (i *BoolItem) Bytes() []byte {
 	if i.value {
 		return []byte{1}
 	}
-	// return []byte{0}
-	// FIXME revert when NEO 3.0 https://github.com/nspcc-dev/neo-go/issues/477
-	return []byte{}
+	return []byte{0}
 }
 
 // TryBytes implements StackItem interface.
diff --git a/pkg/vm/vm_test.go b/pkg/vm/vm_test.go
index 7b911d5d8..4f655870c 100644
--- a/pkg/vm/vm_test.go
+++ b/pkg/vm/vm_test.go
@@ -1505,9 +1505,7 @@ func TestSIZEBool(t *testing.T) {
 	vm.estack.PushVal(false)
 	runVM(t, vm)
 	assert.Equal(t, 1, vm.estack.Len())
-	// assert.Equal(t, makeStackItem(1), vm.estack.Pop().value)
-	// FIXME revert when NEO 3.0 https://github.com/nspcc-dev/neo-go/issues/477
-	assert.Equal(t, makeStackItem(0), vm.estack.Pop().value)
+	assert.Equal(t, makeStackItem(1), vm.estack.Pop().value)
 }
 
 func TestARRAYSIZEArray(t *testing.T) {