diff --git a/quic/core/http/quic_server_session_base_test.cc b/quic/core/http/quic_server_session_base_test.cc
index 13e264d..33a1ab8 100644
--- a/quic/core/http/quic_server_session_base_test.cc
+++ b/quic/core/http/quic_server_session_base_test.cc
@@ -153,10 +153,6 @@
         QuicRandom::GetInstance(), &clock,
         QuicCryptoServerConfig::ConfigOptions());
     session_->Initialize();
-    if (!GetQuicReloadableFlag(quic_version_negotiated_by_default_at_server)) {
-      QuicSessionPeer::GetMutableCryptoStream(session_.get())
-          ->OnSuccessfulVersionNegotiation(supported_versions.front());
-    }
     QuicConfigPeer::SetReceivedInitialSessionFlowControlWindow(
         session_->config(), kMinimumFlowControlSendWindow);
     session_->OnConfigNegotiated();
diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index d6838f3..e987da9 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -333,8 +333,6 @@
       bytes_received_before_address_validation_(0),
       bytes_sent_before_address_validation_(0),
       address_validated_(false),
-      quic_version_negotiated_by_default_at_server_(
-          GetQuicReloadableFlag(quic_version_negotiated_by_default_at_server)),
       use_handshake_delegate_(
           GetQuicReloadableFlag(quic_use_handshaker_delegate2) ||
           version().handshake_protocol == PROTOCOL_TLS1_3) {
@@ -375,9 +373,9 @@
          supported_versions.size() == 1);
   InstallInitialCrypters(server_connection_id_);
 
-  if (quic_version_negotiated_by_default_at_server() &&
-      perspective_ == Perspective::IS_SERVER) {
-    QUIC_RELOADABLE_FLAG_COUNT(quic_version_negotiated_by_default_at_server);
+  // On the server side, version negotiation has been done by the dispatcher,
+  // and the server connection is created with the right version.
+  if (perspective_ == Perspective::IS_SERVER) {
     version_negotiated_ = true;
     framer_.InferPacketHeaderTypeFromVersion();
   }
@@ -764,31 +762,6 @@
     return false;
   }
 
-  if (!quic_version_negotiated_by_default_at_server()) {
-    if (!version_negotiated_ && perspective_ == Perspective::IS_SERVER) {
-      if (!header.version_flag) {
-        // Packets should have the version flag till version negotiation is
-        // done.
-        std::string error_details = quiche::QuicheStrCat(
-            ENDPOINT, "Packet ", header.packet_number.ToUint64(),
-            " without version flag before version negotiated.");
-        QUIC_DLOG(WARNING) << error_details;
-        CloseConnection(QUIC_INVALID_VERSION, error_details,
-                        ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
-        return false;
-      } else {
-        DCHECK_EQ(header.version, version());
-        version_negotiated_ = true;
-        framer_.InferPacketHeaderTypeFromVersion();
-        visitor_->OnSuccessfulVersionNegotiation(version());
-        if (debug_visitor_ != nullptr) {
-          debug_visitor_->OnSuccessfulVersionNegotiation(version());
-        }
-      }
-      DCHECK(version_negotiated_);
-    }
-  }
-
   return true;
 }
 
diff --git a/quic/core/quic_connection.h b/quic/core/quic_connection.h
index b060f87..5d44234 100644
--- a/quic/core/quic_connection.h
+++ b/quic/core/quic_connection.h
@@ -905,10 +905,6 @@
   // Called when version is considered negotiated.
   void OnSuccessfulVersionNegotiation();
 
-  bool quic_version_negotiated_by_default_at_server() const {
-    return quic_version_negotiated_by_default_at_server_;
-  }
-
   bool use_handshake_delegate() const { return use_handshake_delegate_; }
 
  protected:
@@ -1520,9 +1516,6 @@
 
   QuicConnectionMtuDiscoverer mtu_discoverer_;
 
-  // Latched value of quic_version_negotiated_by_default_at_server.
-  const bool quic_version_negotiated_by_default_at_server_;
-
   // Latched value of quic_use_handshaker_delegate2.
   const bool use_handshake_delegate_;
 };
diff --git a/quic/core/quic_connection_test.cc b/quic/core/quic_connection_test.cc
index 4a041d1..035f457 100644
--- a/quic/core/quic_connection_test.cc
+++ b/quic/core/quic_connection_test.cc
@@ -1584,9 +1584,7 @@
     if (perspective == Perspective::IS_SERVER) {
       connection_.set_can_truncate_connection_ids(true);
       QuicConnectionPeer::SetNegotiatedVersion(&connection_);
-      if (GetQuicReloadableFlag(quic_version_negotiated_by_default_at_server)) {
-        connection_.OnSuccessfulVersionNegotiation();
-      }
+      connection_.OnSuccessfulVersionNegotiation();
     }
     QuicFramerPeer::SetPerspective(&peer_framer_,
                                    QuicUtils::InvertPerspective(perspective));
diff --git a/quic/core/quic_crypto_server_stream_test.cc b/quic/core/quic_crypto_server_stream_test.cc
index 8e6afaf..a2f9568 100644
--- a/quic/core/quic_crypto_server_stream_test.cc
+++ b/quic/core/quic_crypto_server_stream_test.cc
@@ -102,10 +102,6 @@
     crypto_test_utils::SetupCryptoServerConfigForTest(
         server_connection_->clock(), server_connection_->random_generator(),
         &server_crypto_config_);
-    if (!GetQuicReloadableFlag(quic_version_negotiated_by_default_at_server)) {
-      server_session_->GetMutableCryptoStream()->OnSuccessfulVersionNegotiation(
-          supported_versions_.front());
-    }
   }
 
   QuicCryptoServerStreamBase* server_stream() {
diff --git a/quic/core/quic_session.cc b/quic/core/quic_session.cc
index 4ab9f6c..109a668 100644
--- a/quic/core/quic_session.cc
+++ b/quic/core/quic_session.cc
@@ -118,8 +118,7 @@
 
   // On the server side, version negotiation has been done by the dispatcher,
   // and the server session is created with the right version.
-  if (connection_->quic_version_negotiated_by_default_at_server() &&
-      perspective() == Perspective::IS_SERVER) {
+  if (perspective() == Perspective::IS_SERVER) {
     connection_->OnSuccessfulVersionNegotiation();
   }
 
diff --git a/quic/quic_transport/quic_transport_server_session_test.cc b/quic/quic_transport/quic_transport_server_session_test.cc
index 2f0a0e8..dfd075e 100644
--- a/quic/quic_transport/quic_transport_server_session_test.cc
+++ b/quic/quic_transport/quic_transport_server_session_test.cc
@@ -75,9 +75,6 @@
         &crypto_config_, &compressed_certs_cache_, &visitor_);
     session_->Initialize();
     crypto_stream_ = session_->GetMutableCryptoStream();
-    if (!GetQuicReloadableFlag(quic_version_negotiated_by_default_at_server)) {
-      crypto_stream_->OnSuccessfulVersionNegotiation(GetVersions()[0]);
-    }
     ON_CALL(visitor_, ProcessPath(_))
         .WillByDefault(DoAll(SaveArg<0>(&path_), Return(true)));
   }
diff --git a/quic/test_tools/crypto_test_utils.cc b/quic/test_tools/crypto_test_utils.cc
index 287e378..308e51c 100644
--- a/quic/test_tools/crypto_test_utils.cc
+++ b/quic/test_tools/crypto_test_utils.cc
@@ -237,10 +237,6 @@
       server_conn, *server_quic_config, client_conn->supported_versions(),
       crypto_config, &compressed_certs_cache);
   server_session.Initialize();
-  if (!GetQuicReloadableFlag(quic_version_negotiated_by_default_at_server)) {
-    server_session.OnSuccessfulVersionNegotiation(
-        client_conn->supported_versions().front());
-  }
   EXPECT_CALL(*server_session.helper(),
               CanAcceptClientHello(testing::_, testing::_, testing::_,
                                    testing::_, testing::_))
diff --git a/quic/tools/quic_simple_server_session_test.cc b/quic/tools/quic_simple_server_session_test.cc
index f19fb02..8e15bcd 100644
--- a/quic/tools/quic_simple_server_session_test.cc
+++ b/quic/tools/quic_simple_server_session_test.cc
@@ -258,10 +258,6 @@
         QuicRandom::GetInstance(), &clock,
         QuicCryptoServerConfig::ConfigOptions());
     session_->Initialize();
-    if (!GetQuicReloadableFlag(quic_version_negotiated_by_default_at_server)) {
-      QuicSessionPeer::GetMutableCryptoStream(session_.get())
-          ->OnSuccessfulVersionNegotiation(supported_versions.front());
-    }
 
     if (VersionHasIetfQuicFrames(transport_version())) {
       EXPECT_CALL(*connection_, SendControlFrame(_))
@@ -619,10 +615,6 @@
         config_, connection_, &owner_, &stream_helper_, &crypto_config_,
         &compressed_certs_cache_, &memory_cache_backend_);
     session_->Initialize();
-    if (!GetQuicReloadableFlag(quic_version_negotiated_by_default_at_server)) {
-      QuicSessionPeer::GetMutableCryptoStream(session_.get())
-          ->OnSuccessfulVersionNegotiation(supported_versions.front());
-    }
     // Needed to make new session flow control window and server push work.
 
     if (VersionHasIetfQuicFrames(transport_version())) {