By December 1936, Hitler Youth membership had reached over five million.[34] That same month, membership became mandatory for "Aryans", under the Gesetz über die Hitlerjugend (Hitler Youth Law).[35] This legal obligation was reaffirmed in March 1939 with the Jugenddienstpflicht (Youth Service Duty), which conscripted all German youths into the Hitler Youth—even if the parents objected.[36] Parents who refused to allow their children to join were subject to an investigation by the authorities.[37] From then on, the vast majority of Germany's teenagers belonged to the Hitler Youth.