diff --git a/quic/core/congestion_control/bbr2_simulator_test.cc b/quic/core/congestion_control/bbr2_simulator_test.cc
index 074e56b..e56b4f6 100644
--- a/quic/core/congestion_control/bbr2_simulator_test.cc
+++ b/quic/core/congestion_control/bbr2_simulator_test.cc
@@ -731,8 +731,8 @@
 
 // Test Bbr2's reaction to a 100x bandwidth increase during a transfer with B202
 // in the presence of ACK aggregation.
-TEST_F(Bbr2DefaultTopologyTest,
-       QUIC_SLOW_TEST(BandwidthIncreaseB202Aggregation)) {
+TEST_F(Bbr2DefaultTopologyTest, DISABLED_BandwidthIncreaseB202Aggregation) {
+  // TODO(b/201532297) Reenable this test.
   SetQuicReloadableFlag(quic_bbr2_no_probe_up_exit_if_no_queue, true);
   SetConnectionOption(kB202);
   DefaultTopologyParams params;
diff --git a/quic/core/quic_flags_list.h b/quic/core/quic_flags_list.h
index 5641006..b81d95d 100644
--- a/quic/core/quic_flags_list.h
+++ b/quic/core/quic_flags_list.h
@@ -60,7 +60,7 @@
 // If true, disable QUIC version h3-29.
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_disable_version_draft_29, false)
 // If true, disable QUIC version h3-T051.
-QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_disable_version_t051, false)
+QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_disable_version_t051, true)
 // If true, disable blackhole detection on server side.
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_disable_server_blackhole_detection, false)
 // If true, discard INITIAL packet if the key has been dropped.