diff --git a/quiche/common/quiche_feature_flags_list.h b/quiche/common/quiche_feature_flags_list.h
index 503784c..05c89e5 100755
--- a/quiche/common/quiche_feature_flags_list.h
+++ b/quiche/common/quiche_feature_flags_list.h
@@ -65,7 +65,7 @@
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_use_alarm_multiplexer, false, false, "Manages all of the connection alarms via QuicAlarmMultiplexer.")
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_use_received_client_addresses_cache, true, true, "If true, use a LRU cache to record client addresses of packets received on server's original address.")
 QUICHE_FLAG(bool, quiche_reloadable_flag_quic_version_negotiation_rfc, false, true, "If true, use the RFC version of the version negotiation transport parameter.")
-QUICHE_FLAG(bool, quiche_restart_flag_quic_support_flow_label2, true, true, "If true, QUIC will support reading and writing IPv6 flow labels.")
+QUICHE_FLAG(bool, quiche_restart_flag_quic_support_flow_label2, false, true, "If true, QUIC will support reading and writing IPv6 flow labels.")
 QUICHE_FLAG(bool, quiche_restart_flag_quic_support_release_time_for_gso, false, false, "If true, QuicGsoBatchWriter will support release time if it is available and the process has the permission to do so.")
 QUICHE_FLAG(bool, quiche_restart_flag_quic_testonly_default_false, false, false, "A testonly restart flag that will always default to false.")
 QUICHE_FLAG(bool, quiche_restart_flag_quic_testonly_default_true, true, true, "A testonly restart flag that will always default to true.")