Depreciation for rental property Driveway

My accountant has been depreciating the cost of an added driveway for my rental property over 15 years.  Everything I've found on-line states that a driveway is considered an improvement to the land and is depreciated over 15 years.  However, Turbo Tax used the default 27.5 years depreciation for a house.  How do I override this incorrect depreciation formula in Turbo Tax?