Disabled attribute won't update after toggled

[cognitom]

Once disabled, the attribute never be updated, with latest Riot.
The example below should toggle each other:

 <btn-group>
  <btn onpush={ toggle } disabled={ isOn }>Turn On</btn>
  <btn onpush={ toggle } disabled={ !isOn }>Turn Off</btn>
</btn-group>
<script>
  this.isOn = false
  toggle (e) {
    this.isOn = !this.isOn
  }
</script>

[cognitom]

Fixed.