Left panel: Evolution of the surface lithium abundance (A(Li)) as a function of central hydrogen abundance (normalised by the initial value) for the lower-mass stars in our sample (G-type stars). The horizontal orange bar indicates the higher limit value for 16Cyg B. Right panel: Same as the left panel, but for the higher-mass stars in our sample (F-type stars) for which undershooting at the base of the convective envelope is necessary to reproduce the surface lithium abundance.