After one of New York City’s largest construction companies admitted to overbilling clients, according to federal prosecutors, it has agreed to pay more than $20 million.

On Thursday, the U.S. Attorney’s office in Brooklyn said that Tishmam Construction’s $20 million payment will include penalties to the federal government as well as restitution to victims.

Prosecutors say that the construction company was charging clients for hours not worked and higher rates than what the clients has bargained for. According to authorities, the practice had been going on for approximately 10 years on projects that included construction on Aqueduct Racetrack, the expansion of the Javits Convention Center, and the One World Trade Center.

Deficiencies in the company’s policies were recognized and safeguards were instituted, and the company cooperated with the probe, according to a spokesman for Tishman.