The Berlin government returned hundreds of flats to the long-term rental market in the first nine months of 2016 as part of its two-year old crackdown on short-term vacation rentals.

Landlords were forced to convert 1,518 illegally rented vacation apartments to long-term residences in the period , the Berlin senate’s office of urban development said in a report quoted by Berliner Morgenpost.

Germany’s capital in 2014 passed a law prohibiting the conversion of residential flats into vacation rentals after advocates blamed services such as AirBnB and VRBO of exacerbating the city’s housing crisis. The new law’s grace period ended in May and landlords now must receive approval from the city before using apartments solely as vacation rentals.

The law is known as the Zweckentfremdungsverbot, which isn’t worth translating because it doesn’t make any more sense in English.

“These initial successes show that the Zweckentfremdungsverbot is a vital instrument to battle the tight situation on the apartment market,” Katrin Lompscher, Berlin’s urban development minister, was quoted by the Morgenpost.

To increase its efficacy, “the instrument will be strengthened and made more resilient,” Lompscher said.

Two-thirds of the apartments now back on the market were reported by neighbors. Some 500 apartments in Kreuzberg-Friedrichshain were among those returned to the market while Mitte accounted for 200.

In the first nine months, the senate reportedly received more than 2,600 applications for licenses but ruled on just 1,167 — it only approved 58. It also threatened to fine another 300 owners operating illegal vacation apartments.

The move isn’t without opposition. Owners of about 1,000 units have appealed the prohibition on their apartments and the owners of 200 filed suite against the city during the period and 215 apartments are currently in the judicial appeal process, according to the paper.

The city now has 62 employees in its 12 boroughs working on lowering the number of unused apartments and battling vacation rentals.