The two "Wyoming"s, along with the "Florida"s and "New York"s were heavily modernized in the 1920s. All six ships were converted to completely oil-fired boilers with equipment taken from the cancelled "South Dakota"-class battleships. The boilers were trunked into a single funnel. These boilers were much more efficient than the coal-fired models the ships had been completed with, and they allowed a significantly greater cruising radius of . The ships were also fitted with anti-torpedo bulges, which improved their underwater defense and also provided additional oil storage capacity. "Wyoming" and "Arkansas" lost their cage main mast, which was replaced by a short tripod mast that carried searchlights and radio antennas. Some of their secondary battery guns were relocated higher in the ship to improve their workability in heavy seas. A sponson for six guns was built into the hull abreast of the conning tower and the eight 3-inch anti-aircraft guns were moved to the top of the sponson. Both ships had their torpedo tubes removed.