Eco-innovations that reduce carbon emissions help advance sustainability transitions in tourism. This article examines the analytical potential of actor-network theory (ANT) to study eco-innovation. ANT assumes that reality consists of actor-networks made of human and non-human elements that perform actors as network effects. We argue that, in a time when climate change is the simultaneous product and producer of human actions, eco-innovation is better understood when research gives the human and non-human elements that perform eco-innovations equal analytical treatment. We therefore develop an ANT-inspired framework, which we apply in a case study to investigate the development of a specific eco-innovation: CARMACAL, a web-based carbon management application in the Dutch travel industry. We find that technological novelty alone is insufficient to instigate transition. CARMACAL affords multiple new practices with opposite implications for socio-economic and environmental sustainability. The practices triggering most industry support are least effective in addressing tourism's climate impacts and vice versa. Examining eco-innovation through ANT helps us put eco-innovation in a different light. Seemingly contradictory practices may be mutually supportive: their individual strengths and weaknesses may help prevent the failure of eco-innovations. This new possibility opens the way for concerted policies strengthening the contribution of eco-innovations to sustainability transitions.