OMAHA, Neb. (AP) — The Trump administration is following through on a plan to allow year-round sales of gasoline mixed with 15% ethanol.

The Environmental Protection Agency announced the change Friday, ending a summertime ban imposed out of concerns for increased smog from the higher ethanol blend. The agency had proposed the change in March.

The change also fulfills a pledge that President Donald Trump made to U.S. corn farmers, who see ethanol as an important driver of demand for their crops. Oil refineries have been seeking exemptions from government requirements to include ethanol in their fuel mixes.

Environmental groups contend the U.S. Clean Air Act prohibits year-round sales of E15, and court challenges are expected.