in the early 1918, matuszewski received a default death sentence from the bolsheviks. in response to this threat, he captured minsk, chasing away the bolshevik garrison, on february 18, 1918. two days later, he became the commander of the city. since the germans had also sentenced him to death, he decided to move to kiev. in april 1918, matuszewski joined the polish military organisation. in may 1918, he participated in the coup directed against general dowbor-muśnicki, who wanted to hand control of the polish i corps to the germans at the fortress of bobrujsk. after the coup failed and the germans disarmed the corps, matuszewski was back in kiev.