\ProvidesFile{iso-authoryear.cbx}[2011/06/08]
\RequireCitationStyle{authoryear}
\renewbibmacro*{cite:labelyear+extrayear}{%
  \iffieldundef{labelyear}
    {}
    {\addcomma\addspace\printtext[bibhyperref]{%
       \printfield{labelyear}%
       \printfield{extrayear}}}}