In this article, we use a contextualized lab experiment to test the effect of non-monetary incentives that can guide harvest professionals into adopting new sustainable harvesting practices. First, we test the effect of signing a declaration that commits wood buyers who voluntarily sign it to act in a sustainable manner. Second, we test the effect of priming by activating a concept of sustainability on subjects’ behaviour. Our results provide evidence that presenting a declaration to sign is effective in inducing subjects to act in a sustainable manner when personal and collective interests are not aligned and there are financial incentives to make decisions that are against environmental sustainability. However, sustainability priming does not have a significant impact on subjects’ behaviour. From a public policy point of view, a declaration is an effective tool and easy to implement by institutions aiming at fostering pro-environmental behaviour.