Vertical_align_engraver::acknowledge_element (Score_element_info i)
{
if (i.origin_grav_l_arr_.size() == 1 &&
- i.elem_l_->is_type_b (Vertical_group_spanner::static_name()) &&
+ dynamic_cast<Vertical_group_spanner *> (i.elem_l_) &&
!i.elem_l_->axis_group_l_a_[Y_AXIS])
{
assert (!valign_p_->contains_b (i.elem_l_));