U.S. construction spending unexpectedly fell in May, pulled down by a decline in outlays on private construction projects.

The Commerce Department said on Wednesday that construction spending dropped 2.1%. Data for April was revised down to show construction outlays decreasing 3.5% instead of declining 2.9% as previously reported.

Economists polled by Reuters had forecast construction spending rebounding 1.0% in May.

Spending on private construction projects dropped 3.3%, offsetting a 1.2% increase in outlays on public projects. Spending on both residential and nonresidential construction products such manufacturing and power plants fell.