diff --git a/quiche/quic/core/quic_flags_list.h b/quiche/quic/core/quic_flags_list.h
index e145be8..c962208 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -82,7 +82,7 @@
 // If true, use next_connection_id_sequence_number to validate retired cid number.
 QUIC_FLAG(quic_reloadable_flag_quic_check_retire_cid_with_next_cid_sequence_number, true)
 // If true, use quiche/common/structured_headers in QuicReceiveControlStream::OnPriorityUpdateFrame().
-QUIC_FLAG(quic_reloadable_flag_quic_priority_update_structured_headers_parser, false)
+QUIC_FLAG(quic_reloadable_flag_quic_priority_update_structured_headers_parser, true)
 // If true, uses conservative cwnd gain and pacing gain when cwnd gets bootstrapped.
 QUIC_FLAG(quic_reloadable_flag_quic_conservative_cwnd_and_pacing_gains, false)
 // When true, defaults to BBR congestion control instead of Cubic.