Normalised order showing the interference pattern caused by internal reflections in the Coudé train of ESPRESSO. Each spectrum in the order has been corrected for telluric contamination, outliers have been masked out, and colour correction has been applied. After these corrections, the order was divided by the out-of-transit baseline. The residual structure shows that UT-1 (out of transit) is likely less affected by the interference pattern than UT-2.