U.S. construction spending recorded its biggest drop in a year in April as investment in both private and public projects fell, but a sharp upward revision to the prior month’s data pointed to underlying strength.

The Commerce Department said on Thursday that construction spending tumbled 1.4 percent. Spending in March was revised to show it jumping 1.1 percent to a record $1.24 trillion.

Economists polled by Reuters had forecast construction spending increasing 0.5 percent in April after a previously reported 0.2 percent drop in March. Construction spending increased 6.7 percent from a year ago.

In April, private construction spending fell 0.7 percent, also the biggest decline in a year, after increasing 1.0 percent in March. Investment in private residential construction fell 0.7 percent after six straight monthly increases.

Spending on private nonresidential structures decreased 0.6 percent in April to its lowest level in almost a year. It was the third