diff --git a/quic/core/chlo_extractor.cc b/quic/core/chlo_extractor.cc
index 201c6df..4b38ad2 100644
--- a/quic/core/chlo_extractor.cc
+++ b/quic/core/chlo_extractor.cc
@@ -31,8 +31,7 @@
 
   // QuicFramerVisitorInterface implementation
   void OnError(QuicFramer* /*framer*/) override {}
-  bool OnProtocolVersionMismatch(ParsedQuicVersion version,
-                                 PacketHeaderFormat form) override;
+  bool OnProtocolVersionMismatch(ParsedQuicVersion version) override;
   void OnPacket() override {}
   void OnPublicResetPacket(const QuicPublicResetPacket& /*packet*/) override {}
   void OnVersionNegotiationPacket(
@@ -106,8 +105,7 @@
       chlo_contains_tags_(false),
       connection_id_(EmptyQuicConnectionId()) {}
 
-bool ChloFramerVisitor::OnProtocolVersionMismatch(ParsedQuicVersion version,
-                                                  PacketHeaderFormat /*form*/) {
+bool ChloFramerVisitor::OnProtocolVersionMismatch(ParsedQuicVersion version) {
   if (!framer_->IsSupportedVersion(version)) {
     return false;
   }
diff --git a/quic/core/http/end_to_end_test.cc b/quic/core/http/end_to_end_test.cc
index 93eceb0..96b7ee3 100644
--- a/quic/core/http/end_to_end_test.cc
+++ b/quic/core/http/end_to_end_test.cc
@@ -215,7 +215,6 @@
         override_client_connection_id_(nullptr),
         expected_server_connection_id_length_(kQuicDefaultConnectionIdLength) {
     SetQuicFlag(FLAGS_quic_supports_tls_handshake, true);
-    SetQuicRestartFlag(quic_no_server_conn_ver_negotiation2, true);
     client_supported_versions_ = GetParam().client_supported_versions;
     server_supported_versions_ = GetParam().server_supported_versions;
     negotiated_version_ = GetParam().negotiated_version;
diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 485b4c9..c11d0c0 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -298,7 +298,7 @@
           &stats_,
           GetQuicReloadableFlag(quic_default_to_bbr) ? kBBR : kCubicBytes,
           kNack),
-      version_negotiation_state_(START_NEGOTIATION),
+      version_negotiated_(false),
       perspective_(perspective),
       connected_(true),
       can_truncate_connection_ids_(perspective == Perspective::IS_SERVER),
@@ -322,12 +322,7 @@
       processing_ack_frame_(false),
       supports_release_time_(false),
       release_time_into_future_(QuicTime::Delta::Zero()),
-      no_version_negotiation_(supported_versions.size() == 1),
       retry_has_been_parsed_(false) {
-  if (perspective_ == Perspective::IS_SERVER &&
-      supported_versions.size() == 1) {
-    QUIC_RESTART_FLAG_COUNT(quic_no_server_conn_ver_negotiation2);
-  }
   QUIC_DLOG(INFO) << ENDPOINT << "Created connection with server connection ID "
                   << server_connection_id
                   << " and version: " << ParsedQuicVersionToString(version());
@@ -356,8 +351,7 @@
   uber_received_packet_manager_.set_max_ack_ranges(255);
   MaybeEnableSessionDecidesWhatToWrite();
   MaybeEnableMultiplePacketNumberSpacesSupport();
-  DCHECK(!GetQuicRestartFlag(quic_no_server_conn_ver_negotiation2) ||
-         perspective_ == Perspective::IS_CLIENT ||
+  DCHECK(perspective_ == Perspective::IS_CLIENT ||
          supported_versions.size() == 1);
   InstallInitialCrypters();
 }
@@ -537,8 +531,7 @@
 }
 
 bool QuicConnection::OnProtocolVersionMismatch(
-    ParsedQuicVersion received_version,
-    PacketHeaderFormat form) {
+    ParsedQuicVersion received_version) {
   QUIC_DLOG(INFO) << ENDPOINT << "Received packet with mismatched version "
                   << ParsedQuicVersionToString(received_version);
   if (perspective_ == Perspective::IS_CLIENT) {
@@ -546,64 +539,11 @@
     QUIC_BUG << ENDPOINT << error_details;
     CloseConnection(QUIC_INTERNAL_ERROR, error_details,
                     ConnectionCloseBehavior::SILENT_CLOSE);
-    return false;
-  }
-  if (no_version_negotiation_) {
-    // Drop old packets that were sent by the client before the version was
-    // negotiated.
-    return false;
-  }
-  DCHECK_NE(version(), received_version);
-
-  if (debug_visitor_ != nullptr) {
-    debug_visitor_->OnProtocolVersionMismatch(received_version);
   }
 
-  switch (version_negotiation_state_) {
-    case START_NEGOTIATION:
-      if (!framer_.IsSupportedVersion(received_version)) {
-        SendVersionNegotiationPacket(form != GOOGLE_QUIC_PACKET);
-        version_negotiation_state_ = NEGOTIATION_IN_PROGRESS;
-        return false;
-      }
-      break;
-
-    case NEGOTIATION_IN_PROGRESS:
-      if (!framer_.IsSupportedVersion(received_version)) {
-        SendVersionNegotiationPacket(form != GOOGLE_QUIC_PACKET);
-        return false;
-      }
-      break;
-
-    case NEGOTIATED_VERSION:
-      // Might be old packets that were sent by the client before the version
-      // was negotiated. Drop these.
-      return false;
-
-    default:
-      DCHECK(false);
-  }
-
-  // Store the new version.
-  framer_.set_version(received_version);
-  framer_.InferPacketHeaderTypeFromVersion();
-
-  version_negotiation_state_ = NEGOTIATED_VERSION;
-  visitor_->OnSuccessfulVersionNegotiation(received_version);
-  if (debug_visitor_ != nullptr) {
-    debug_visitor_->OnSuccessfulVersionNegotiation(received_version);
-  }
-  QUIC_DLOG(INFO) << ENDPOINT << "version negotiated "
-                  << ParsedQuicVersionToString(received_version);
-
-  MaybeEnableSessionDecidesWhatToWrite();
-  no_stop_waiting_frames_ =
-      VersionHasIetfInvariantHeader(received_version.transport_version);
-
-  // TODO(satyamshekhar): Store the packet number of this packet and close the
-  // connection if we ever received a packet with incorrect version and whose
-  // packet number is greater.
-  return true;
+  // Server drops old packets that were sent by the client before the version
+  // was negotiated.
+  return false;
 }
 
 // Handles version negotiation for client connection.
@@ -626,7 +566,7 @@
     debug_visitor_->OnVersionNegotiationPacket(packet);
   }
 
-  if (version_negotiation_state_ != START_NEGOTIATION) {
+  if (version_negotiated_) {
     // Possibly a duplicate version negotiation packet.
     return;
   }
@@ -781,8 +721,7 @@
     return false;
   }
 
-  if (version_negotiation_state_ != NEGOTIATED_VERSION &&
-      perspective_ == Perspective::IS_SERVER) {
+  if (!version_negotiated_ && perspective_ == Perspective::IS_SERVER) {
     if (!header.version_flag) {
       // Packets should have the version flag till version negotiation is
       // done.
@@ -795,14 +734,14 @@
       return false;
     } else {
       DCHECK_EQ(header.version, version());
-      version_negotiation_state_ = NEGOTIATED_VERSION;
+      version_negotiated_ = true;
       framer_.InferPacketHeaderTypeFromVersion();
       visitor_->OnSuccessfulVersionNegotiation(version());
       if (debug_visitor_ != nullptr) {
         debug_visitor_->OnSuccessfulVersionNegotiation(version());
       }
     }
-    DCHECK_EQ(NEGOTIATED_VERSION, version_negotiation_state_);
+    DCHECK(version_negotiated_);
   }
 
   return true;
@@ -1894,7 +1833,7 @@
     return false;
   }
 
-  if (version_negotiation_state_ != NEGOTIATED_VERSION) {
+  if (!version_negotiated_) {
     if (perspective_ == Perspective::IS_CLIENT) {
       DCHECK(!header.version_flag || header.form != GOOGLE_QUIC_PACKET);
       if (!VersionHasIetfInvariantHeader(framer_.transport_version())) {
@@ -1904,7 +1843,7 @@
         // forward secure.
         packet_generator_.StopSendingVersion();
       }
-      version_negotiation_state_ = NEGOTIATED_VERSION;
+      version_negotiated_ = true;
       visitor_->OnSuccessfulVersionNegotiation(version());
       if (debug_visitor_ != nullptr) {
         debug_visitor_->OnSuccessfulVersionNegotiation(version());
diff --git a/quic/core/quic_connection.h b/quic/core/quic_connection.h
index 947209e..9bb00b2 100644
--- a/quic/core/quic_connection.h
+++ b/quic/core/quic_connection.h
@@ -464,8 +464,7 @@
 
   // From QuicFramerVisitorInterface
   void OnError(QuicFramer* framer) override;
-  bool OnProtocolVersionMismatch(ParsedQuicVersion received_version,
-                                 PacketHeaderFormat form) override;
+  bool OnProtocolVersionMismatch(ParsedQuicVersion received_version) override;
   void OnPacket() override;
   void OnPublicResetPacket(const QuicPublicResetPacket& packet) override;
   void OnVersionNegotiationPacket(
@@ -1310,21 +1309,8 @@
   // to send packets.
   QuicSentPacketManager sent_packet_manager_;
 
-  // The state of connection in version negotiation finite state machine.
-  enum QuicVersionNegotiationState {
-    START_NEGOTIATION = 0,
-    // Server-side this implies we've sent a version negotiation packet and are
-    // waiting on the client to select a compatible version.  Client-side this
-    // implies we've gotten a version negotiation packet, are retransmitting the
-    // initial packets with a supported version and are waiting for our first
-    // packet from the server.
-    NEGOTIATION_IN_PROGRESS,
-    // This indicates this endpoint has received a packet from the peer with a
-    // version this endpoint supports.  Version negotiation is complete, and the
-    // version number will no longer be sent with future packets.
-    NEGOTIATED_VERSION
-  };
-  QuicVersionNegotiationState version_negotiation_state_;
+  // Indicates whether connection version has been negotiated.
+  bool version_negotiated_;
 
   // Tracks if the connection was created by the server or the client.
   Perspective perspective_;
@@ -1418,11 +1404,6 @@
   // Time this connection can release packets into the future.
   QuicTime::Delta release_time_into_future_;
 
-  // Indicates whether server connection does version negotiation. Server
-  // connection does not support version negotiation if a single version is
-  // provided in constructor.
-  const bool no_version_negotiation_;
-
   // Payload of most recently transmitted IETF QUIC connectivity
   // probe packet (the PATH_CHALLENGE payload). This implementation transmits
   // only one PATH_CHALLENGE per connectivity probe, so only one
diff --git a/quic/core/quic_connection_test.cc b/quic/core/quic_connection_test.cc
index 5201b5a..c7f6e07 100644
--- a/quic/core/quic_connection_test.cc
+++ b/quic/core/quic_connection_test.cc
@@ -743,7 +743,6 @@
 
   void SetSupportedVersions(const ParsedQuicVersionVector& versions) {
     QuicConnectionPeer::GetFramer(this)->SetSupportedVersions(versions);
-    QuicConnectionPeer::SetNoVersionNegotiation(this, versions.size() == 1);
     writer()->SetSupportedVersions(versions);
   }
 
diff --git a/quic/core/quic_framer.cc b/quic/core/quic_framer.cc
index 83ea19b..5b061d7 100644
--- a/quic/core/quic_framer.cc
+++ b/quic/core/quic_framer.cc
@@ -1513,7 +1513,7 @@
 
   if (header.version_flag && header.version != version_) {
     if (perspective_ == Perspective::IS_SERVER) {
-      if (!visitor_->OnProtocolVersionMismatch(header.version, header.form)) {
+      if (!visitor_->OnProtocolVersionMismatch(header.version)) {
         RecordDroppedPacketReason(DroppedPacketReason::VERSION_MISMATCH);
         return true;
       }
diff --git a/quic/core/quic_framer.h b/quic/core/quic_framer.h
index 18420f1..3a3faa1 100644
--- a/quic/core/quic_framer.h
+++ b/quic/core/quic_framer.h
@@ -76,8 +76,8 @@
   // |quic_version_|. The visitor should return true after it updates the
   // version of the |framer_| to |received_version| or false to stop processing
   // this packet.
-  virtual bool OnProtocolVersionMismatch(ParsedQuicVersion received_version,
-                                         PacketHeaderFormat form) = 0;
+  virtual bool OnProtocolVersionMismatch(
+      ParsedQuicVersion received_version) = 0;
 
   // Called when a new packet has been received, before it
   // has been validated or processed.
diff --git a/quic/core/quic_framer_test.cc b/quic/core/quic_framer_test.cc
index c2aea06..26e756f 100644
--- a/quic/core/quic_framer_test.cc
+++ b/quic/core/quic_framer_test.cc
@@ -213,8 +213,7 @@
     retry_token_ = QuicMakeUnique<std::string>(std::string(retry_token));
   }
 
-  bool OnProtocolVersionMismatch(ParsedQuicVersion received_version,
-                                 PacketHeaderFormat /*form*/) override {
+  bool OnProtocolVersionMismatch(ParsedQuicVersion received_version) override {
     QUIC_DLOG(INFO) << "QuicFramer Version Mismatch, version: "
                     << received_version;
     ++version_mismatch_;
diff --git a/quic/core/quic_ietf_framer_test.cc b/quic/core/quic_ietf_framer_test.cc
index e00ced6..23ec1cb 100644
--- a/quic/core/quic_ietf_framer_test.cc
+++ b/quic/core/quic_ietf_framer_test.cc
@@ -100,8 +100,8 @@
                      QuicConnectionId /*new_connection_id*/,
                      QuicStringPiece /*retry_token*/) override {}
 
-  bool OnProtocolVersionMismatch(ParsedQuicVersion /*received_version*/,
-                                 PacketHeaderFormat /*form*/) override {
+  bool OnProtocolVersionMismatch(
+      ParsedQuicVersion /*received_version*/) override {
     return true;
   }
 
diff --git a/quic/core/quic_versions.cc b/quic/core/quic_versions.cc
index 349b373..23b6094 100644
--- a/quic/core/quic_versions.cc
+++ b/quic/core/quic_versions.cc
@@ -433,7 +433,6 @@
   SetQuicReloadableFlag(quic_eliminate_static_stream_map_3, true);
   SetQuicReloadableFlag(quic_tolerate_reneging, true);
   SetQuicReloadableFlag(quic_simplify_stop_waiting, true);
-  SetQuicRestartFlag(quic_no_server_conn_ver_negotiation2, true);
   SetQuicRestartFlag(quic_do_not_override_connection_id, true);
   SetQuicRestartFlag(quic_use_allocated_connection_ids, true);
 }