Rise minimal shutter speed in Auto ISO

[lv]

Hello. I shoot a lot with canons 85 1.8. I love to use Auto ISO feature in AV mode. But the minimal shutter speed in ISO speed settings in Canon 6D is only 1/250. Unfortunately, some of shots with non IS 85 lens get motion blur while shooting 1/250 shutter speed. If it is possible it woulds really help to have a 1/400 or more speed setting for all longer lens users who wish to use Auto ISO.

Regards,
LV