The European Court of Justice, the European Union’s highest court, ruled on Tuesday that the Dutch cannot deport a Russian national receiving cancer care in the Netherlands as his treatment involves the use of medical cannabis, which is outlawed in Russia.

The 34-year-old man has a rare form of blood cancer and has been receiving treatment in the Netherlands since 2013. He claims medical cannabis has alleviated about 70% of his pain symptoms and his doctors say there is no better treatment option available.

The Luxembourg-based court found that EU precludes countries from deporting anyone if there is a serious risk that doing so will jeopardize their ongoing medical care.

Deportations are not legal if ‘there are substantial grounds for believing that returning that national would expose him or her, on account of appropriate care not being available in the receiving country, to a real risk of a rapid, significant and permanent increase in the pain caused by his or her illness,’ the court wrote in a press release.

Officials for the justice ministry argued that stopping cannabis treatment didn’t create an imminent threat to the man’s life and it wasn’t proven to be an effective remedy.

Medical marijuana has been available in the Netherlands since 2003 and can be prescribed by a doctor for a variety of ailments, including Tourette Syndrome and chronic pain.