Some option agreements allow the early exercise of options, turning them into restricted stock. Because the value is usually low at seed stage, a good strategy is to exercise and then file 83(b) on the restricted stock. In this case, assuming you have this provision in your stock agreement, it avoids the mess of this exact scenario.

83(b) is applicable to options, if the options grant allows for early exercise, and you do exercise early (before the options have vested).

Or if the option grant has early exercise.