How can I stop Unity from smoothing imported FBX animations?

The artists on the project are working in 3DSMax and are trying to create instant transitions, moving objects from one point to another over zero frames. In 3DSMax it means the animation curves look like vertical lines.

However when these are imported into Unity, the animation curves are changed to bezier smoothed ones. This means that all the instant jumps are smoothed out to take 1 to 3 frames. The transition is visible to the player, they see a one-frame flash as the object transitions to its new position.

Is there a trick to stopping this from happening? I've played with Unity's in-engine animation system, and I know it supports non-bezier curves.