Abstract. Typical open source software (OSS) development projects are organized around technically talented developers, whose communication is based on technical aspects and source code. Decision-making power is gained through proven competence and activity in the project, and non-technical enduser opinions are too many times neglected. In addition, also human-computer interaction (HCI) specialists have encountered difficulties in trying to participate in OSS projects, because there seems to be no clear authority and responsibility for them. In this paper, based on HCI and OSS literature, we introduce an extended OSS development project organization model that adds a new level of communication and roles for attending human aspects of software. The proposed model makes the existence of HCI specialists visible in the projects, and promotes interaction between developers and the HCI specialists in the course of a project.