The fablab of Paris-Diderot University first opened its doors at the end of 2016, within an institutional context aiming at promoting a number of digital devices and systems that would allow Paris-Diderot to become the ideal “university-in-the-city”. How did this institutional discourse of digital development in secondary education find its counterpart in the daily practices that gave birth to the Paris-Diderot, and influenced its development? By exploring this fablab’s pioneering days, the institutional and human factors that shaped its creation, we seek to understand how actors made this imperative their own, were able to “hijack” it to some extent, or in some cases, had to yield to hierarchical constraints. To do so, the article analyses a number of choices made by the fablab founders and questions their reasons and their evolutions.