A round baler includes a housing which has a housing part and an ejection flap which is pivotably mounted on this housing part about a bearing axis, and drivable pressing means which are allocated to the housing part and the ejection flap and which define a pressing chamber on the peripheral side, wherein the ejection flap is adjustable by means of a first adjusting apparatus such that when the ejection flap is opened an ejection opening is able to be formed between the housing part and the ejection flap and a dimension of the ejection flap is adjustable. The housing part comprises a retaining roller. The retaining roller is arranged so as to be adjustable between a resting position and a working position in which the retaining roller adopts a position disposed within the ejection opening.