The logarithmic coefficients
of an analytic and univalent function
in the unit disk
with the normalization
are defined by
. Recently, D. K. Thomas [Proc. Amer. Math. Soc. 144 (2016), 1681–1687] proved that
for functions in a subclass of close-to-convex functions (with argument
) and claimed that the estimate is sharp by providing a form of an extremal function. In the present paper, we point out that such extremal functions do not exist and the estimate is not sharp by providing a much more improved bound for the whole class of close-to-convex functions (with argument
). We also determine a sharp upper bound of
for close-to-convex functions (with argument
) with respect to the Koebe function.