Flemish Language Decree: workers can invoke void provisions
The fact that the employment contract is absolutely null and void due to a violation of the Flemish Language Decree does not prevent the employee from basing their claim on the void provisions of the employment contract that are in their favour. However, the employee must take the full provision into account.

Facts
The employee's employment contract was drafted in Dutch in accordance with the Flemish Language Decree of 19 July 1973. After the employer was acquired by a British company, that company added English-language annexes to the employment contract.
The employee was subsequently dismissed with payment of severance pay. Later, the employee brought a claim for payment of a bonus based on provisions drafted in English.
Procedure on the merits
The Flemish Language Decree stipulates that documents intended for employees which are drafted in a language other than Dutch are absolutely null and void. However, Article 10, 5th paragraph of the Flemish Language Decree states that such nullification may not be detrimental to the employee.
Both the Labour Court and the Labour Court of Appeal therefore ruled that the English-language provisions of the employment contract were null and void, but nonetheless accepted that the employee could invoke the void provisions insofar as they were in his favour. Consequently, they granted the request for the payment of the bonus.
The employer subsequently filed an appeal before the Court of Cassation against the judgment of the Labour Court of Appeal.
Court of Cassation ruling
The Court of Cassation confirmed that an employee can invoke the void provisions of the employment contract in his favour and base his claim on them.
In his opinion, the advocate general noted, "If an employee wishes to rely on a provision favourable to him, he must observe the entire clause. He cannot, in one and the same clause, withhold certain parts and set aside others." Thus, an employee cannot simultaneously claim the payment of a bonus but set aside the related condition of attendance in the same clause.
Takeaway
Provisions that do not comply with the rules of the Flemish Language Decree are absolutely null and void. However, the employee may rely on void provisions that are in his favour. In that case, the employee must comply with the provision in its entirety.
Source: Cass. 3 February 2025, S.18.0020.N.