South Korea’s Supreme Court on Thursday ruled that conscientious objection – moral and religious beliefs – is a valid reason to refuse the country’s mandatory military service, Reuters reported. The landmark ruling is expected to affect more than 900 conscientious objectors who are on trial.

For almost 65 years, South Korea has made it mandatory for every able-bodied man between the ages of 18 and 35 to complete around two years of military service. Those who refuse to do so usually spend 18 months in prison. According to AFP, around 19,000 conscientious objectors have been jailed since 1950, especially Jehovah’s Witnesses – a Christian denomination.

“It is the majority opinion of the Supreme Court that conscientious objection is...a valid reason [to refuse conscription],” AFP quoted chief Supreme Court Justice Kim Myeong-su as saying. Punishing these objectors is an excessive constraint to an individual’s freedom of conscience, the judge added.

The court was hearing the case of Oh Seung-hun, a Jehnovah’s Witness who had refused to join the military as doing so went against biblical teaching. Oh was called to military service in 2013, but a trial court found him guilty after he refused. He said the ruling was a huge step forward in ending the policy of imprisoning people who refuse military service on grounds of faith.

According to South Korea’s Military Service Act, if a person enlisted in the draft refuses without a “valid reason”, they can be sentenced to jail for up to three years. Earlier in 2018, South Korea’s Constitutional Court had directed the government to introduce alternative social service for conscientious objectors by 2019.

South Korea is technically still at war with the North as the 1950 to 1953 Korean War ended in a ceasefire instead of a peace treaty. However, there has been a recent thaw in the relations between the two countries, with an inter-Korean military pact being signed in September.