The theory of unforeseeability, from the perspective of hardship, is regulated in Article 138 of the Turkish Code of Obligations. In the repealed Code of Obligations, no general rule addressing this concept existed. However, the rule of good faith was considered as a ground for contract adaptations. This research analyzes a decision of the Turkish Supreme Court’s Assembly of Civil Cham- bers rather than explaining the elements of adaptation in a didactic manner. § 313 of the German Civil Code is considered as the source for Article 138 of the Turkish Code of Obligations. The spirit of the theory of unforeseeability aims to compensate the negative effects that may result from anchoring in the principle of pacta sund servanda by way of using the instrument of balancing justice. In order to explain this spirit in detail, in addition to the German Law, the French Law and Swiss Law were also considered. In cases relating to adaptation claims, the Turkish Supreme Court’s Assembly of Civil Chambers has been making the same justification in its decisions since 2000 and rejecting them on the basis of a presupposed reason that there has always been an economic crisis in Turkey. In the given case, a tragic nuclear accident occurred in Japan, after the outbreak of great mortgage crisis in the USA, which had destructive effects globally. Therefore, it became extremely difficult for the consumer to pay off his credit debt, since the Japanese Yen overvalued against the Turkish Lira. It is obvious that the capability of a con- sumer to foresee does not include a global economic crisis or nuclear accident. The attitude of the Turkish Supreme Court in this regard, defending interests of banking sector intentionally or unintentionally, must be criticized. At the first step, this legal shield for banking sector was applied only for commercial credits. With the aid of this criticized decision, starting from its effective date, this shield is also applicable to consumer credits. This biased and the ‘ratio legis’- ignoring attitude, which assumes that there is always an economic crisis in Turkey and holds banks above anybody by disregarding the distinction between consumer and merchandiser, must be abandoned.