diff --git a/quiche/quic/core/quic_flags_list.h b/quiche/quic/core/quic_flags_list.h
index ee7d169..d9333b2 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -58,7 +58,7 @@
 // If true, include stream information in idle timeout connection close detail.
 QUIC_FLAG(quic_reloadable_flag_quic_add_stream_info_to_idle_close_detail, true)
 // If true, lowers the minimum packet size to that in the spec.
-QUIC_FLAG(quic_restart_flag_quic_allow_smaller_packets, true)
+QUIC_FLAG(quic_restart_flag_quic_allow_smaller_packets, false)
 // If true, quic server will send ENABLE_CONNECT_PROTOCOL setting and and endpoint will validate required request/response headers and extended CONNECT mechanism and update code counts of valid/invalid headers.
 QUIC_FLAG(quic_reloadable_flag_quic_verify_request_headers_2, true)
 // If true, reject or send error response code upon receiving invalid request or response headers. This flag depends on --gfe2_reloadable_flag_quic_verify_request_headers_2.