<jats:p>Joachimski et al. carried out geochemical investigations to study seawater temperature changes and their potential triggers across the Permian-Triassic Boundary (PTB). Unfortunately, in our opinion, an incorrect biochronology was applied to define the PTB, and the existing alternative was not considered, nor the reasoning explained. As a consequence, Joachimski et al. report diachronous temperature changes for the investigated Chanakhchi section with respect to the global stratotype section and point (GSSP) in Meishan, China. This discrepancy disappears when the, in our view, correct position of the PTB is adopted by using the proper biochronology.</jats:p>