  Data of the Grande extension of the KASCADE experiment allows us to study
extensive air showers induced by primary cosmic rays with energies above
10^{16} eV. The energy of an event is estimated in terms of the number of
charged particles (Nch ) and the number of muons (N{\mu} ) measured at an
altitude of 110 m a.s.l. While a combination of the two numbers is used for the
energy, the ratio defines the primary mass (group). The spectrum of the
combined light and medium mass components, recently measured with
KASCADE-Grande, was found to be compatible with both a single power-law and a
broken power-law in the energy range between 10^{16.3} and 10^{18} eV. In this
contribution we will present the investigation of possible structures in the
spectrum of light primaries with increased statistics both from a larger data
set including more recent measurements and by using a larger fiducial area than
in the previous study. With the better statistical accuracy and with optimized
selection criteria for enhancing light primaries we have found evidence for a
hardening (ankle) of the spectrum of the light component at an energy of
10^{17.08+-0.08} eV.
