STUTTGART, Germany — Army and Air Force Exchange Service customers in Germany will not be able to purchase fuel at AAFES gas stations or use their fuel ration card at off-post Esso stations for an 11-hour period Thursday morning, according to a news release.

The scheduled system outage will occur between 3 a.m. and 2 p.m., the AAFES release said. During the shutdown, AAFES also will not be able to issue or replace fuel ration cards and customers won’t be able to do any transactions on their accounts.

The outage is necessary for AAFES to perform a critical upgrade to the exchange mainframe system, according to the release.