Working conditions may need to be changed over time. In our law, making changes in the working conditions determined in the employment contract and other sources is subject to various procedures and principles.Desiring to make changes in working conditions can sometimes bring about the termination of amendment. Changes to working conditions that may be subject to termination of change are substantive changes. In terms of nonsubstantial changes, it is accepted that the employer has the will within the scope of the management right. However, there is no definite criterion for the changes that exceed the employer's management right limits. The Supreme Court's jurisprudence gives the greatest idea about the fundamental nature of the amendments.In the study, the concept of annulment of the amendment and its scope are mentioned, and it has been tried to shed light on the fundamental changes in which this annulment may come to the agenda, with the opinions in the doctrine and legal regulations, especially the judicial decisions.