Regarding the unavoidable mass transport contributions, especially pronounced for good catalysts like Pt, we pointed out that the Koutecký-Levich relationship should not be used for mass transport correction at small overpotentials, e.g. the micropolarization exchange current density, a common mistake in the electrochemical literature. This relationship is per definition only valid for electrochemically irreversible reactions, such as in the Tafel region, and is thus not appropriate for the micropolarization region, as it does not compensate for the contribution of reverse currents. We provide an alternative equation, allowing for appropriate correction of mass transport effects in the micropolarization region and hope that it is embraced by the electrochemical community.