A rollable screen comprises a rotatable winding tube for a screen mounted for rotation in a stationary mounting assembly and a spring for loading said winding tube in a direction for winding the screen onto the winding tube. A first end of said spring is connected to the winding tube and a second end is connected to a mounting part positioned within the winding tube and connected to the stationary mounting assembly. Said mounting part comprises projecting locking elements for cooperation with corresponding locking members of the mounting assembly and for a rotation relative thereto between a first rotational position in which the mounting part can be inserted in or removed from the mounting assembly, and a second rotational position in which the locking elements and locking members prevent any translational movement of the rollable screen relative to the stationary mounting assembly.