  Some crucial issues about a recently proposed estimator for the proportion of
true null hypotheses ($\pi_0$) under discrete setup are discussed. An estimator
for $\pi_0$ is introduced under the same setup. The estimator may be seen as a
modification of a very popular estimator for $\pi_0$, originally proposed under
the assumption of continuous test statistics. It is shown that adaptive
Benjamini-Hochberg procedure remains conservative with the new estimator for
$\pi_0$ being plugged in.
