The present invention relates to a method for depositing an adherent zinc coating onto a zinc-containing magnesium alloy substrate in order to render the surface suitable for electroplating. The coatings are applied from a pyrophosphate-based zinc electrolyte solution containing a small quantity of fluoride ions. Depending on the zinc and aluminum content of the magnesium alloy, the zinc electrolyte solution is applied by immersion deposition or electrolytically.