An end cap for a wiper of a window of a vehicle having at least one flexible supporting element and a blade design to be applied against the window is disclosed. The end cap includes a housing for receiving an end portion of the flexible supporting element. The end cap also has at least one means for locking the end portion of the flexible supporting element in an engaged position in the housing, and an outer wall delimiting the cap as well as an access orifice to the locking means, the locking means including a portion forming a longitudinal stop facing the flexible supporting element, a first face extending between the housing and the outer wall and a second face opposite the orifice. The locking means include an element that emerges at the junction between the first face and the portion and that extends at least longitudinally beyond the portion.