A screening arrangement for a roof window to be installed in an inclined or flat roof of a building to cover an opening of the window in a mounted condition of the screening arrangement, where the screening arrangement comprises: a screening device including a top casing, a screening body having two side edges, a first end portion and a second end portion, said screening body being movable in a longitudinal direction between a non-screening position, in which the screening body is substantially accommodated in the top casing, and a number of screening positions in which the screening body is deployed from the top casing and covers the opening partially or entirely, and two side rails (63, 64) configured to extend substantially perpendicularly to the top casing in a mounted condition of the screening arrangement, the top casing and the two side rails (63, 64) defining an outer perimeter of the screening device, and a corner cover assembly including a first and a second corner cover element (81, 82), each covering an opening in-between the top casing and a respective one of the two side rails (63, 64), the first and the second corner cover element (81, 82) having a top surface and a bottom surface, such that, in the mounted condition of the screening arrangement, the top surface faces towards an exterior and the bottom surface faces towards an interior, characterised in that each first and second corner cover element (81, 82) has such dimensions (D1, D2) that an overlap is provided between the corner cover element (81, 82) and the underlying top casing and side rail (63, 64) in the mounted condition of the screening arrangement, and that the bottom surface of each first and second corner cover element (81, 82) is configured to absorb incident light on the bottom surface by providing the bottom surface as a surface of dark colour, such as black. a screening device including a top casing, a screening body having two side edges, a first end portion and a second end portion, said screening body being movable in a longitudinal direction between a non-screening position, in which the screening body is substantially accommodated in the top casing, and a number of screening positions in which the screening body is deployed from the top casing and covers the opening partially or entirely, and two side rails (63, 64) configured to extend substantially perpendicularly to the top casing in a mounted condition of the screening arrangement, the top casing and the two side rails (63, 64) defining an outer perimeter of the screening device, and a corner cover assembly including a first and a second corner cover element (81, 82), each covering an opening in-between the top casing and a respective one of the two side rails (63, 64), the first and the second corner cover element (81, 82) having a top surface and a bottom surface, such that, in the mounted condition of the screening arrangement, the top surface faces towards an exterior and the bottom surface faces towards an interior, characterised in that each first and second corner cover element (81, 82) has such dimensions (D1, D2) that an overlap is provided between the corner cover element (81, 82) and the underlying top casing and side rail (63, 64) in the mounted condition of the screening arrangement, and that the bottom surface of each first and second corner cover element (81, 82) is configured to absorb incident light on the bottom surface by providing the bottom surface as a surface of dark colour, such as black.