We compare b-values in the frequency–magnitude law for the foreshocks and long-term seismicity. Foreshocks are considered in two non-overlapping time intervals, preceding a main shock: (i) last hours; (ii) last days. Statistical analysis of the regional and global earthquake catalogs shows, that in either of these intervals b-value drops by a half, compared to long-term seismicity. This extends the previous results by Molchan and Dmitrieva [Molchan, G., Dmitrieva, O., 1990. Dynamics of the magnitude–frequency relation for foreshocks. Phys. Earth Planet. Inter. 61, 99–112], who have found such a drop a few hours before a mainshock. Our results concern a statistical regularity, not necessarily seen for each individual sequence of foreshocks.