Paradox theory has not yet considered how paradoxes interact when they are brought together. To explore such knotting we investigate coopetition for sustainability, when competitors collaborate to address environmental concerns. We use a case study of three examples of collaborative activities between housing companies in Belarus to display how these two paradoxes are knotted together. We find that coopetition brings less tension and is used as a means to address stronger sustainability tensions, enabling firms to partially achieve ‘two needs with one deed’. Based on our findings we suggest that how knotting appears is affected by the type of paradoxes involved, the strength and dynamics of their tensions, and their relationships to each other. We conclude with a call for more research particularly in more competitive settings and with other types of paradoxes.