Foreign permanent residents over the age of 20 may naturalize as ROK citizens after residing in South Korea for more than five years and demonstrating proficiency in the Korean language. The residency requirement is reduced to three years for individuals with a South Korean parent who were not already ROK citizens, and two years for applicants with South Korean spouses. This is further reduced to one year for applicants who have been married to South Koreans for more than three years. Minor children cannot naturalize independently, but may apply with a foreigner parent who is also naturalizing. Successful naturalization applicants are typically required to renounce their previous nationalities within one year, unless they naturalized through marriage. Individuals who are granted nationality by the Ministry of Justice specifically for their exceptional occupational ability or contributions made to the country are also exempt from this requirement. Exempt individuals must alternatively make a declaration not to exercise their foreign nationality within South Korea.