The legal protection of whistle-blowers has recently received considerable attention from the legal community. Due to several scandals such as Luxleaks and Panama Papers, the legal status of whistle-blowers has become a starting point of discussion for governments, legal scholars, and regulators. In October 2019, the European Union took a significant step by adopting the Directive 2019/1937 on the protection of persons who report breaches of Union law. This Directive is significant as it is the first EU text offering protection to whistle-blowers at the EU level. This article will analyse the legal bases of the Directive and argue that the fragile nature of several of these bases means that they may be challenged before the Court of Justice of the European Union. Secondly, the goal of the article is to examine the role of the right to freedom of expression, as interpreted by the European Court of Human Rights, with respect to the Directive.