One example apparatus includes an adaptation logic configured to determine a reference voltage adaptation for a flash memory device as a function of a current reference voltage in use by the flash memory device and a difference of bit error types experienced by the flash memory device. In one embodiment, the difference of bit error types compares a number of zero to one bit errors to a number of one to zero bit errors. In one embodiment, the adaptation logic is further configured to determine a reference voltage adaptation that will shift the reference voltage towards a threshold voltage (Vth) distribution associated with a zero value by an amount that is proportional to the difference of bit errors.