The present invention relates to a roll bar for a cab-less construction machine, in particular a vibration roller, which is implemented so it is adjustable in height between an operating position and a transport position. The roll bar includes a pivotable tube bow, which comprises two vertical pivot tubes; two stand tubes, which are fixedly connected to the frame of the construction machine; two connection elements, via which the pivot tubes are connected to the stand tubes, the connection elements each comprising a stop surface, against which the pivot tube can be moved to, in particular pressed, in the operating position; a lock for clamping the pivot tube against the connection element in the operating position; a welding surface, to which the stand tube is materially bonded; and a pivot joint having a pivot axis, around which the pivot tubes are pivotable. The connection elements each comprise two sheet-metal parts, which are symmetrical to one another, the stop surfaces and the welding surfaces being implemented as edge profiles of the sheet-metal parts, and the welding surfaces being oriented essentially horizontally.