Belgium has recently decided to integrate the Consortium of European Social Science Data Archives (CESSDA). The Social Sciences Data Archive (SODA) project aims at tackling the different challenges entailed by the setting up of a new research infrastructure in the form of a data archive. The SODA project involves an archival institution, the State Archives of Belgium, which, like most other large archival repositories around the world, work with Encoded Archival Description (EAD) for managing their metadata. There exists at the State Archives a large pipeline of programs and procedures that processes EAD documents and channels their content through different applications, such as the online catalog of the institution. Because there is a chance that the future Belgian data archive will be part of the State Archives and because DDI is the most widespread metadata standard in the social sciences as well as a requirement for joining CESSDA, the State Archives have developed a DDI-to-EAD crosswalk in order to re-use the State Archives' infrastructure for the needs of the future Belgian service provider. Technical illustrations highlight the conceptual differences between DDI and EAD and how these can be reconciled or escaped for the purpose of a data archive for the social sciences.