Wind stop device

In order to increase stability in a wind deflector device for motor vehicles, in particular for convertible vehicles, comprising a wind deflector with a wind deflector frame extending in a vehicle transverse direction and a flow-obstructing element closing a frame opening of the wind deflector frame, wherein the wind deflector is foldable by at least one joint about a wind deflector folding axis between an unfolded position and a folded position, a cover pivotally connected to the wind deflector about a pivot axis with a cover frame extending in the vehicle transverse direction and away from the pivot axis and with a flow-obstructing element closing a frame opening of the cover frame, wherein the cover frame is foldable by at least one joint about a cover folding axis between an unfolded position and a folded position, it is proposed that at least one of the joints in the unfolded position be blockable by a blocking device against folding into the folded position.