The invention describes an adapter for a handheld machine tool, comprising a locking unit (40), which can be releasably and fixedly attached to a housing (10) of a handheld machine tool, and a rotatably mounted shaft (32), which can be connected in a rotationally fixed manner to a drive shaft (20) of the handheld machine tool, wherein the locking unit (40) has at least one means (42, 62) for a latching connection.