This article discusses the harmonization of penal provisions concerning money laundering in the European Union (EU), in particular, the recent Commission proposal for a Directive on tackling money laundering by criminal law (COM(2016) 826 final). The perspective is both legal and political, pointing out to the different legal solutions in the European Union and analyzing the development from a European integration perspective, particularly in terms of a so -called spill-over process, whereby integration in one field lea ds to integration in adjacent fields. We put forward two main arguments in this article: (1) We argue that in order for the spill-over to succeed in a field crucial for national sovereignty suc h as criminal law, spill-over needs to be complemented with securitization and policy laundering, the latter referring to the phenomenon whereby issues are agreed at an international non-binding arena in order to later introduce these “international standards” into binding legislation. (2) We argue that harmonization in the money laundering context provides an example of a successful spill-over enhanced by policy laundering and securitization; tackling money laundering ostensibly requires spilling over European integration also in the field of crimina l law, a core issue of national sovereignty. A testament to this is the fact that European countries have even harmonized their criminalization of self-laundering, although punishable self-laundering has been previously considered contrary to the general doctrines and principles of criminal law in many countries. A case in point is Finland, the only country bound by the proposed directive where parties to the crime are not punished for money laundering, except in rare cases and there i s no case law for self-laundering (Section 11 Chapter 32 of the Criminal Code of Finland).