Boreal peatlands storge huge amounts of carbon. The carbon in peatlands is fixed by atmospheric carbon dioxide (CO2) uptake by an extraordinary plant that dominates the vegetation in peatlands for thousands of years: peatmoss. It is uncertain how future climate change affects peatmoss growth and associated carbon uptake of peatlands. Here, the question of how able peatmosses are able to cope with drought stress plays a central role. We examined various mechanisms through which peatmosses stabilize their water availability. With experiments in a climate chamber and in Swedish peatlands we determined the importance of rainwater retention in the plants and shrinkage of the peatmoss carpet. With these data and by creating a simulation model we quantified how these processes contribute to the stabilization of water availability in a future climate. Our results illustrate that fine-scale ecohydrological processes increase peatland resistance to climate change more than expected.