The present analysis deals with the controvery, surrounding the premixed-flame regime of activation-energy aymptotics, which was raised by Law et al, claiming that an additional constraint is required to uniquely determine the flame structure. The activation energy asymptotics procedure which employs the distinguished limit of the premixed-flame regime is derived step by step to point out be origin of the controversy. It is shown by directly comparing the flame structures obtained by different closure assumptions that the premixed flame region indeed leads to assign solution to the flame structure and no extra physical constraint is necessary to close the problem.