Governance rules in software development projects help to prioritize and manage their development tasks, and contribute to the long-term sustainability of the project by clarifying how core and external contributors should collaborate in order to advance the project during its whole lifespan. Despite their importance, specially in Open Source Software (OSS) projects, these rules are usually implicit or scattered in the project documentation/tools (e.g., tracking-systems or forums), hampering the correct understanding of the development process. We propose to enable the explicit definition and enforcement of governance rules for OSS projects. We believe this brings several important benefits, including improvements in the transparency of the process, its traceability and the semi-automation of the governance itself. Our approach has been implemented on top of Mylyn, a project-management Eclipse plug-in supporting most popular tracking-systems.