Sustainability is an ambiguous and open-ended concept with many different meanings. Researchers as well as practitioners often express frustration with this fact and frequently call for more consistent, measurable, and univocal definitions of sustainability to ensure agreement, mutual understanding, and collective action (Jahdi & Acikdilli, 2009; Kolk, 2003). This essay, by contrast, explores the potential of appreciating and embracing ambiguity in the sustainability arena. We argue that lack of a clear-cut sustainability definition has potential to mobilize stakeholders to challenge existing understandings and explore new ideas and practices. Accepting conceptual ambiguity, in other words, is not necessarily to evade responsibility or critique. Whereas discursive closure may bind the concept to the past and make an organization blind to new and unexpected issues of sustainability problems, an open-ended conceptualization may stimulate sensitivity, quick adaption, and innovative solutions. We refer to this practice as “license to critique.” Instead of presuming to provide final answers to sustainability issues, sustainability program can, as a license to critique, authorize and invite stakeholders to participate, challenge, and debate.