Between 1918 and 1921 he was imprisoned at least six times by the Bolsheviks. In 1919, he voluntarily enlisted in the Red Army to combat the counter-revolutionary white army, but he was imprisoned in Kharkiv for refusing to disarm workers and suppress protest. On 8 March 1921, during the Kronstadt uprising, he was arrested in Moscow by the Cheka, along with other members of the Nabat confederation. Maximoff was locked in Taganka prison, where he was sentenced to death for spreading anarcho-syndicalist propaganda. After a hunger strike, on December 1921 he managed to attract the attention of workers visiting the Red Trade Union Congress. As a result of pressure from the international community, he and 10 other anarchists were released from prison and expelled from the country.