A system (100) for positioning a working tool (21) in a wellbore (1). The positioning system (100) comprises a casing element (110) with a marker (111, 112, 113) provided on an inner surface, the marker (111, 112, 113) having a distinct diameter different from the inner diameter of the casing element (110). The system further comprises a positioning tool (120) with a latching element (121, 122) adapted to form a latch (115) with the marker (111, 112, 113), and a force detector (130) adapted to detect an axial latching force (FL) applied to a tubing string (20) from the latch (115) when the casing element (110) is located within the wellbore (1) and the force detector (130) is located at a surface (2) outside the wellbore (1).