The use of informal instruments in international governance has raised concerns about their legal status, including questioning whether they should be approved by domestic parliaments. These concerns are often dismissed by reference to the legal non-bindingness and claimed harmlessness of the instruments. Yet informal instruments have various effects in society as legal and political communications. These effects emphasize the need to address the democratic deficit of informal instruments resulting from their isolation from the parliaments and the undemocratic nature of international decision-making. This article proposes a twofold approach to address this deficit. At the domestic level, better engagement of parliamentarians through deliberative ‘feedback loops’ established between the parliament and the government should be sought, complemented by parliamentary approval of important informal instruments. At the international level, so-called ‘culture of deliberativism’, that is, a turn to deliberation by embracing deliberative democratic standards for better representation of public opinions, is proposed to induce democratic sensibility into international decision-making and its products. The legal status and potential bindingness should not be the focus of public debate on informal instruments; their subtle effects and undemocratic origin are the real ‘phantom menace’ in need of addressing.