diff --git a/quic/core/http/end_to_end_test.cc b/quic/core/http/end_to_end_test.cc
index aba00ab..56a130c 100644
--- a/quic/core/http/end_to_end_test.cc
+++ b/quic/core/http/end_to_end_test.cc
@@ -199,7 +199,6 @@
     AddToCache("/foo", 200, kFooResponseBody);
     AddToCache("/bar", 200, kBarResponseBody);
     // Enable fixes for bugs found in tests and prod.
-    SetQuicReloadableFlag(quic_donot_change_queued_ack, true);
     SetQuicReloadableFlag(quic_fix_server_pto_timeout, true);
     SetQuicReloadableFlag(quic_do_not_retransmit_immediately_on_zero_rtt_reject,
                           true);
diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 68af365..3544457 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -4191,18 +4191,13 @@
 
 void QuicConnection::PostProcessAfterAckFrame(bool send_stop_waiting,
                                               bool acked_new_packet) {
-  if (no_stop_waiting_frames_) {
-    if (GetQuicReloadableFlag(quic_donot_change_queued_ack) &&
-        packet_creator_.has_ack()) {
-      QUIC_RELOADABLE_FLAG_COUNT(quic_donot_change_queued_ack);
-    } else {
-      uber_received_packet_manager_.DontWaitForPacketsBefore(
-          last_decrypted_packet_level_,
-          SupportsMultiplePacketNumberSpaces()
-              ? sent_packet_manager_.GetLargestPacketPeerKnowsIsAcked(
-                    last_decrypted_packet_level_)
-              : sent_packet_manager_.largest_packet_peer_knows_is_acked());
-    }
+  if (no_stop_waiting_frames_ && !packet_creator_.has_ack()) {
+    uber_received_packet_manager_.DontWaitForPacketsBefore(
+        last_decrypted_packet_level_,
+        SupportsMultiplePacketNumberSpaces()
+            ? sent_packet_manager_.GetLargestPacketPeerKnowsIsAcked(
+                  last_decrypted_packet_level_)
+            : sent_packet_manager_.largest_packet_peer_knows_is_acked());
   }
   // Always reset the retransmission alarm when an ack comes in, since we now
   // have a better estimate of the current rtt than when it was set.
diff --git a/quic/core/quic_connection_test.cc b/quic/core/quic_connection_test.cc
index e751f7b..d8d3013 100644
--- a/quic/core/quic_connection_test.cc
+++ b/quic/core/quic_connection_test.cc
@@ -10918,13 +10918,7 @@
                     .ack_frame->packets.Contains(QuicPacketNumber(2)));
   }));
   ProcessFramesPacketAtLevel(9, frames, ENCRYPTION_FORWARD_SECURE);
-  if (GetQuicReloadableFlag(quic_donot_change_queued_ack)) {
-    EXPECT_TRUE(writer_->ack_frames()[0].packets.Contains(QuicPacketNumber(2)));
-  } else {
-    // ACK frame changes mid packet serialiation!
-    EXPECT_FALSE(
-        writer_->ack_frames()[0].packets.Contains(QuicPacketNumber(2)));
-  }
+  EXPECT_TRUE(writer_->ack_frames()[0].packets.Contains(QuicPacketNumber(2)));
 }
 
 TEST_P(QuicConnectionTest, DonotExtendIdleTimeOnUndecryptablePackets) {