Accomplishment of purpose and loss of purpose fall under the concept of irregularity of purpose as per the systematic we follow in this work. Another concept which falls under the scope of irregularity of purpose is the purpose becoming meaningless. Accomplishment of purpose and loss of purpose being handled basically under this work fall within the scope of subsequent objective impossibility (Turkish Code of Obligations Art. 136) which is among the irregularities of performance. When this provision in question is applied to the cases of accomplishment of purpose and loss of purpose in which the debtor made expenses until that moment, unfair results occur. Because as per the Article 136 of the Turkish Code of Obligations, debtor is discharged from its obligation and loses its right to demand counter claim from the creditor or has to return the counter claim that he has received. For this reason in the cases of accomplishment of purpose and loss of purpose in which the debtor made expenses until that moment, in our opinion implicit legal gap has to be accepted to exist and in conclusion the provision in question should not be applied to these cases by following the method of limitation fit for purpose. The legal gap that occurs here should be filled by the judge by creating law as per the Article 1 of The Turkish Civil Code. In our opinion, the rule that the judge will create should be for the debtor being able to demand the counter claim but to deduct his own obligation which he has not performed from the counter claim.