Civilian innovation is often said to be an important facilitator in the development of Lethal Autonomous Weapon Systems (LAWS). This claim is held up as both a reason to ban LAWS urgently, and why a ban would be impractical. But we know little about how this dynamic plays out in practice. Theoretical insights on technology transfer can help to analyse the situation. They suggest that obtaining and utilising the civilian technology is harder than often assumed. Civil-military cooperation is hindered by the stark differences between the civilian and defence industries. Business practices are out of sync, there are few social ties between the two worlds, innovative cultures do not translate, and many civilian engineers resist cooperation with the military. Additionally, defence still needs to modify civilian technologies to meet military standards and develop military-exclusive applications of autonomy. While civilian innovation thus advances what is technologically possible, this does not automatically translate into major advances or rapid diffusion of LAWS.