He later moved to Medan, in northern Sumatra, where he established the newspaper Matahari Terbit; the newspaper advocated workers rights and criticised the area's large Dutch-owned plantations.
Dia kemudian pindah ke Medan, Sumatera Utara, di mana ia mendirikan surat kabar Matahari Terbit; koran yang mengaspirasi hak-hak pekerja dan mengkritik perkebunan milik Belanda yang besar di daerah itu.