The de Blasio administration says it has forced some of the city’s worst landlords to make repairs by invoking a decades-old law.

Back in May, the city said it would stop paying rent for public assistance recipients living in the so-called “Dirty Dozen,” 12 buildings that had more than 2,000 violations, including leaks, mold and broken windows. The Spiegel Law allows the city to do this if conditions are considered “dangerous, hazardous or detrimental to life and health.”

“The tool worked because in 10 of the 12 buildings the conditions were addressed; substantial numbers of violations were corrected right away,” said Steven Banks, Social Services Commissioner.

The city plans to deliver on its promise and begin withholding rent payments, around $5,000 a month, in the remaining two buildings in Manhattan and the Bronx, where repairs haven’t been made.