Florida Gov. Rick Scott signed a bill that tightened gun rules in the state.

On Friday, Senate Bill 7026—or the Marjory Stoneman Douglas High School Public Safety Act— became law in Florida which raises the legal age of firearm purchases to 21.

The bill is the first significant piece of gun control legislation passed after 17 people were killed at a Parkland, Fla. high school on Feb. 14.

Scott signed the bill surrounded by the families of the victims of the school shooting.

The bill also implements a three day waiting period on gun purchases, as well as allows teachers to be armed, with permission from the local sheriff and school districts.

The new law comes after weeks of debate about gun legislation in the country.

Students who survived the massacre have been calling for politicians to reject funding from the NRA and to enact stricter gun control.