  The AMS-02 collaboration has released preliminary data on the antiproton
fraction in cosmic rays. The surprisingly hard antiproton spectrum at high
rigidity has triggered speculations about a possible primary antiproton
component originating from dark matter annihilations. In this note, we employ
newly available AMS-02 boron to carbon data to update the secondary antiproton
flux within the standard two-zone diffusion model. The new background permits a
considerably better fit to the measured antiproton fraction compared to
previous estimates. This is mainly a consequence of the smaller slope of the
diffusion coefficient favored by the new AMS-02 boron to carbon data.
