Entering AGI when Efiling first time as married separate instead of jointly in TurboTax question

We have always filed married jointly, but this year we want to file married separate, so when it asks my AGI for identification (to efile) from last year it will obviously be wrong as it's combined with spouse.  Do I say that I DIDN'T file a return last year in the TurboTax question?  That seems odd, does that question mean I didn't file as separate?  Very confusing.