In 1941, Bieberbach requested that Teichmüller be released from his military duties in order to continue teaching at the University of Berlin. This request was granted and he was able to teach at the university from 1942 to early 1943. After the German defeat at Stalingrad in February 1943, however, Teichmüller left his position in Berlin and volunteered for combat on the Eastern Front, entering a unit which became involved in the Battle of Kursk. In the beginning of August, he received furlough when his unit reached Kharkov. His unit was surrounded by Soviet troops and largely wiped out by late August, but in early September he attempted to rejoin them. He is reported to have reached somewhere east of the Dnieper but west of Kharkov (most likely Poltava), when he was killed in action on 11 September 1943.