In the future, if businesses want to innovate, IT will have to play a substantial role. Furthermore, innovating with IT will most likely imply opening up the innovation channel and collaborating with various kinds of external partners, as digital platforms and eco-systems involving various actors arise. According to prior research, emphasizing external innovation collaboration bears the risk of inhibiting internal innovation. As the ability to innovate with IT becomes a key differ-ential factor in almost every industry, business managers – especially in non-IT firms – must cultivate the entrepreneurial role of their IT departments and the respective employees. There-fore, the question arises of how the focus on external innovation sources and the emphasis on internal innovativeness of IT professionals relate to each other. Prior research has generated conflicting results on this issue. With our large-scale (n = 354) empirical analysis, we provide evidence that firm openness fosters the entrepreneurial behavior of IT professionals. Further-more, this impact is mediated by the absorptive capacity of the IT unit. Consequently, as our model shows, valuable external knowledge can be integrated for internal innovation purposes, thus driving both IT professionals’ willingness to act entrepreneurially as well as their perceived ability to do so.