Method for operating an assistance system of a motor vehicle and assistance system

The invention relates to a method (12) for operating an assistance system (2) of a motor vehicle (4), in which a further motor vehicle (22) is detected and a first future trajectory (28) is assigned to the further motor vehicle (22). Furthermore, an activated turn signal light (32) of the further motor vehicle (22) is detected and a second future trajectory (36) is assigned to the further motor vehicle (22), which deviates from the first future trajectory (28). The invention furthermore relates to an assistance system (2) of a motor vehicle (4).