State e-filing

Federal Return not due until July 15, and I owe tax, so I'm delaying filing. But I am getting a state refund and would like to file immediately. TurboTax won't let me e-file my state return until my federal return has been filed. Why not?  This should be fixed, ESPECIALLY this year, when federal return due date is delayed by 3 months, but state filing date remains unchanged.