Carb model throttle cable connection to carb linkage

Hi

Where the throttle cable connects to the carb linkage, it travels through a slotted part where the return Spring is.

Q how is the slotted part supposed to hold its self in?

Some how it has come out and the throttle cable came away, strangely this seams to of happened while sat on the drive for a couple of weeks, it's dark but I first thought the cable had failed but found this and just popped it back In and went for a drive. But don't won't it falling out again.