The invention relates to a wiper device for a motor vehicle window, comprising a wiper arm adapter unit (10a-10e) and a wiper blade adapter unit (12a-12e), which in an installed state create a form fit, and further comprising a longitudinal guide unit (20a-20e) for guiding the wiper arm adapter unit (10a-10e). According to the invention, the wiper device comprises a locking means (14a-14e) which is movably mounted on the wiper blade adapter unit (12a-12e) and is provided so as to limit the freedom of movement of the wiper arm adapter unit (10a-10e) in the installed state at least substantially in a longitudinal direction (16a-16e).