Devices for turning sheets in a rotary printing machine are described. The devices have a storage drum for handling sheets, which are each held by a holding device, and a turning drum is disposed downstream of the storage drum and has a holding device for engaging a rear edge of the sheet to be turned. An operation of detaching the sheet to be turned from the storage drum and carrying it along by the turning drum leads to the formation of a pressure reduction in an area formed between the sheet to be turned, the storage drum and the turning drum. The pressure reduction is compensated for by supplying ambient air, blast air and/or compressed air. The turning device has a channel and/or a passage orifice connected to an inner chamber of the turning drum. Via the channel and/or passage orifice air can be sucked and/or blown into the reduced-pressure area.