Game Controller for Nintendo 64 N64 System

This controller works but the joystick is problematic. After pushing down on the joystick, then letting go, it would send a signal as if I was pressing "up" even though I wasn't touching the joystick at all.Depending on the game this might be fine. I didn't notice any problems at all when playing Mario Kart 64 (where "up" on the joystick doesn't do anything), but the wonkiness made playing Mario 64 very difficult. I'll be returning the controller for a refund.