The Supreme Court ruled on 1 May 2015 that if the employer and employee agree on a longer period of notice for the employee than the statutory notice period of one month, they also have to agree (in writing) on a longer period of notice for the employer. The notice period of the employer then has to be twice as long as the notice period of the employee. If they fail to do so, the employee can nullify the agreed period of notice. In that case, the employee has to comply with the statutory notice period of one month. It is important to note that varying provisions can be provided for in a collective labour agreement.