diff --git a/loop.c b/loop.c
index 9052261..b3e9de3 100644
--- a/loop.c
+++ b/loop.c
@@ -485,9 +485,7 @@ void read_dc (int auth_file_fd, int id, unsigned ver) {
 
 void empty_auth_file (void) {
   char *ip = tgl_state.test_mode ? TG_SERVER_TEST : TG_SERVER;
-  static char s[20];
-  sprintf (s, "DC%d", tgl_state.test_mode ? TG_SERVER_TEST_DC : TG_SERVER_DC);
-  bl_do_dc_option (tgl_state.test_mode ? TG_SERVER_TEST_DC : TG_SERVER_DC, strlen (s), s, strlen (ip), ip, 443);
+  bl_do_dc_option (tgl_state.test_mode ? TG_SERVER_TEST_DC : TG_SERVER_DC, 0, "", strlen (ip), ip, 443);
   bl_do_set_working_dc (tgl_state.test_mode ? TG_SERVER_TEST_DC : TG_SERVER_DC);
 }