OP *
Perl_ck_concat(pTHX_ OP *o)
{
- if (cUNOPo->op_first->op_type == OP_CONCAT)
- o->op_flags |= OPf_STACKED;
+ OP *kid = cUNOPo->op_first;
+ if (kid->op_type == OP_CONCAT && !(kUNOP->op_first->op_flags & OPf_MOD))
+ o->op_flags |= OPf_STACKED;
return o;
}