Lindqvist volunteered for military training in Germany in the 3rd Company of 27th Jäger Battalion (Finland) on 10 October 1915, from where he was transferred with 53 other men to the Battalion's Communication Department, established on 2 October 1917. He took part in the fighting in the First World War on the eastern front of Germany on the Misse River, the Gulf of Riga and the Aa River, where he was wounded on 7 January 1917.