Bank of Japan (BoJ) governor Toshihiko Fukui said today he saw no need to change the central bank's view on inflation following changes in the way the figures are compiled.
"As the economy continues to expand gradually, aggregate demand is exceeding supply. In such an environment, consumer prices are expected to be on a positive trend even under the new calculation method," Mr Fukui said.
"There is no need to change our assessment on prices because of the data revision."
Consumer price data issued last month suggested inflation is more subdued than was thought, sending Japanese government bond yields sharply lower.
On Friday the BoJ left monetary policy unchanged for the second month in a row, keeping the key overnight call rate target at 0.25 per cent in a unanimous decision by its nine-member board.
The central bank also issued a monthly report saying the economy is expanding moderately, keeping its assessment unchanged from the previous month. In July, the BoJ raised interest rates for the first time in six years.