India's Supreme Court ruled Wednesday that a man having sex with a wife under the age of 18 constitutes rape.

The landmark ruling changed an exception to a previous law which did not criminalize sex with minors if the two were married, declaring Wednesday that 18 is the age of consent for "all purposes."

The court did not rule on marital rape, which is not illegal in India.

Though child marriage is illegal in India, the non-governmental organization Independent Thought petitioned the top court to rule on the issue of sex with minor brides, saying New Delhi must face the reality that it is widespread throughout the country.

Over a quarter of Indian women between the ages of 20 and 24 reported being married before they were 18, according to a report by the National Commission for the Protection of Child Rights and the charity Young Lives.

The number of underage brides has declined minimally in rural areas over the past 15 years, and actually increased in urban areas, according to the report.