As of 1 May 2016, the amendments on the Social Penal Code entered into force (cfr. our web alerts of March and April 2016). Specifically, with regard to the prevention of violence, moral and sexual harassment at work, different sanctions took effect. As almost every non-respect (or incorrect application) of the obligations is henceforth sanctioned, employers are strongly encouraged to comply with the rules on the prevention of psychosocial risks at work. In addition, another important change was the (re)introduction of sanctions against workers (or the self-employed or civil servants) who perform undeclared work, even if they do not receive replacement incomes. Such a possibility has existed since 2009, but never effectively entered into force.