Reduced PIONIER interferometric data for ZZ CMi. The left plot shows the squared visibilities (V²), while the right one shows the closure phases (T3PHI) in degrees. The colours correspond to the various baselines (B, expressed in terms of the wavelengths, λ), while the black line is the simple fit of a uniform diameter. The turquoise stars are the fit corresponding to a Roche-lobe filling (and, hence, deformed) star. They are mostly different from the black line in the closure phases.