US President Donald Trump said on Wednesday that he has instructed the Department of Justice to look into oil companies for not lowering gasoline pump prices in line with falling crude costs, and accused the companies of “gouging” customers. Trump did not name any companies in his social media post, which came after midnight. The White House and the Justice Department (DOJ) did not respond to a request for further comment outside regular business hours.

The president complained that prices at the pump haven’t dropped sharply enough despite a sharp slump in crude prices since the Iran peace deal went into effect.

The president seems surprised that gas prices haven’t magically returned to normal.