Russia's Constitutional Court on Monday approved amendments proposed by President Vladimir Putin to the country's basic law, giving him the option of serving two further terms in office.
The Constitutional Court published the ruling on its website and immediately sent the ruling to Putin, who could now stay in power until 2036.
The court issued a speedy decision after Putin signed the final reform package on Saturday, though it had a week to consider its ruling.
Putin, 67, last week backed a last-minute proposal by the first woman in space, Valentina Tereshkova, to add an amendment to the reform package allowing his possible return to the Kremlin after 2024.
Under the current constitution he is not allowed to serve another presidential term, having served two consecutive stints from 2012.
The new constitution would allow him reset his term-limit clock back to zero, paving the way for him to stay in power until 2036.
The bill subsequently sailed through the upper house and regional parliaments as required last week.
The Russian leader had proposed changes to the constitution in January but until last week denied that he was seeking to extend his rule.
His spokesman Dmitry Peskov said Putin changed his mind because of global instability.
The amendments also include stipulations banning gay marriages and protecting the "historic truth" of Russia's role in World War II.