EU Directive 2017/541 of 15 March 2017 on combating terrorism requires member states to criminalize certain conduct. Belgium implemented the Directive by creating several terrorist offences, which resemble the wording of the Directive. However, some of these offences are beyond the scope of the Directive. Since the Directive already is quite broad and vague, this means the Belgian offences are even broader and sometimes also vaguer. This paper gives a detailed description of the existing Belgian terrorism offences, pointing out issues of broadness and vagueness, as well as overlap between the different offences. This ambiguity seems to be at odds with the legality principle which requires clear and well-defined offences. The paper concludes that Belgium should have implemented the wording of the Directive more precisely. The EU in turn could review the necessity and wording of the different terrorism offences in the Directive. Having fewer offences which are crafted more precisely would already go a long way in solving the ambiguity of these offences.