Its parliament Sweden today approved a new law banning actions linked to extremist organizations, strengthening its anti-terrorist legislation. This change was a requirement of Turkey in order to approve Sweden’s accession to NATO.

The law criminalizes “participation in a terrorist organization” and will come into effect on June 1.

Presenting the bill last February, Justice Minister Gunnar Strömer said it “significantly widens the scope of the law” compared to previous legislation. Even simple logistical support to a terrorist organization will now be considered a crime, Stromer explained.

In November, Sweden amended its constitution to move forward with reforming its anti-terror law. Until then, this reform conflicted with the constitutionally guaranteed right to freedom of association.

From 2017 the Stockholm has tightened its anti-terror legislation. The attack was triggered by an Uzbek man who had pledged allegiance to the Islamic State and ran over pedestrians with his truck on a shopping street in the Swedish capital, killing five people.

Turkey has refused to approve Sweden’s NATO membership, accusing it of harboring “terrorists” and in particular members of the Kurdistan Workers’ Party (PKK). Ankara often denounces pro-Kurdish demonstrations in Sweden but Stromer assured that “participating in a demonstration or gathering will not be considered a criminal act.”