In this proceedings we study the sensitivity of the ESSnuSB experiment to probe quantum decoherence. ESSnuSB is a future long-baseline neutrino oscillation experiment which aims to measure $\delta_{\rm CP}$ by probing the second oscillation maximum. Using the open quantum system formalism for decoherence, we have shown that the sensitivity of ESSnuSB to constrain the decoherence parameters is better than MINOS but comparable to DUNE. We have also shown that the CP measurement capability of ESSnuSB is robust in presence of decoherence.