Il contributo è destinato agli Studi in Onore di Francesco Santoni, di prossima pubblicazione.

The paper analyzes the regulation of the extension of the fixed-term contract in the regulatory framework outlined by Legislative Decree n. 81/2015, before and after the changes made by l. n. 96/2018 (c.d. "Dignity Decree"). Starting from the absence of a sharp rule about the form that the extension must cover, the author outlines the reasons why the written form is needed for the validity of the deed, especially in the cases where the extension of the term of duration does not require a justification. This constraint is derived from a systematic interpretation of the rules established by the articles 21 et seq., Legislative Decree no. 81/2015, showing that the use of the written form is a measure to protect the weak contractor against the risk of the abuse deriving from the succession of the fixed term relationships. Its adoption is therefore necessary in order to guarantee the effectiveness of the measures against the abuses imposed by the EU law.