Russian lawmakers have approved legislation in line with President Vladimir Putin’s new Constitution which will give lengthy prison terms for calling to cede territory in what is believed to be a warning to those who question Russia’s annexation of Crimea.

The current law, adopted after Moscow seized Crimea from Ukraine in 2014, jails Russians for similar calls to relinquish territory for up to five years. 

Russia’s lower house of parliament adopted the package of so-called “territorial integrity” bills in its second and third readings Wednesday, two weeks after it was first submitted. 

The bills label Russians who repeatedly “violate Russia’s territorial integrity, including alienating part of its territory” as “extremists” and jails them to between six and 10 years in prison.

Under Putin’s amendments that passed in a nationwide vote on July 1, it is now unconstitutional to give any part of Russian territory away to a foreign power. 

In addition to annexing Crimea from Ukraine in 2014, Russia has been involved in a decades-long territorial dispute with Japan over a chain of Pacific islands it seized after World War II.

Russia’s upper house of parliament, which meets for the last time Friday before taking a summer break, needs to back the “territorial integrity” legislation in a single round of voting before Putin can sign it into law.

Legal experts have warned that the legislation risks further eroding freedom of speech in Russia.