This paper unpacks resource mobilisation for biorefineries by studying investment decisions of incumbent pulp and paper firms in Sweden and Finland. The analysis highlights that the limited adoption of biorefinery technologies can be attributed to both insufficient abilities (lack of needed competencies and partnerships) and interests (preference for improving existing technologies) by pulp and paper incumbents. Drawing on the technological innovation system perspective complemented with insights from the management literature on the role of incumbents in technological change, four issues are empirically identified as important for improving resource mobilisation for biorefinery technologies: establishing loosely coupled divisions in pulp and paper firms; creating internal markets for new bioproducts aimed at further technological development; entering purchasing agreements with downstream actors; and investing in new managerial competencies.