Taking point of departure in the ambitious framework for 'safe and just operating spaces' for social-ecological systems, this paper explores the applicability of this conceptual framing. Specifically, we draw attention to limitations in the conceptualisation of justice as a question of attaining a minimal level of (material) wellbeing. With an empirical case from Laos, we apply a broader notion of environmental justice based on interconnected dimensions of distribution, procedure and recognition to examine the dynamic relationship between 'safe' and 'just' at village level, and we question how 'boundaries' of social and ecological sustainability are conceptualized and determined. Our findings illustrate important considerations for the way conservation interventions are rationalized and designed, in particular for the way social and environmental sustainability are portrayed and how governance is envisaged to function locally. This paper contributes to current sustainability debates on how to explore and integrate justice dimensions in development and conservation within human-defined planetary boundaries.