diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5bc4e6638968eb2e70221fe87a71632dc18429bb..416d9a27594d1c7a2470cbd0c84a318f45a946ca 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,8 @@ All notable changes to this project are documented below.
 The format is based on [keep a changelog](http://keepachangelog.com) and this project uses [semantic versioning](http://semver.org).
 
 ## [Unreleased]
-
+### Added
+- Add final notification sent to sockets closed via single socket option.
 
 ## [3.7.0] - 2021-09-28
 ### Added
diff --git a/server/core_notification.go b/server/core_notification.go
index 5ac2d99762449c342ac7ceb7fdb4a0e7784659fe..4746dcbd8b12e4f3b941d0906cbe58fc018d8589 100644
--- a/server/core_notification.go
+++ b/server/core_notification.go
@@ -39,6 +39,7 @@ const (
 	NotificationCodeGroupAdd         int32 = -4
 	NotificationCodeGroupJoinRequest int32 = -5
 	NotificationCodeFriendJoinGame   int32 = -6
+	NotificationCodeSingleSocket     int32 = -7
 )
 
 type notificationCacheableCursor struct {
diff --git a/server/pipeline_match.go b/server/pipeline_match.go
index b111cc381c541342240c52ba70a434ef8c46ce7d..b099c903a13727f898debbed01750d86fb9f1c59 100644
--- a/server/pipeline_match.go
+++ b/server/pipeline_match.go
@@ -227,7 +227,12 @@ func (p *Pipeline) matchJoin(logger *zap.Logger, session Session, envelope *rtap
 				Username: session.Username(),
 				Format:   session.Format(),
 			}
-			p.tracker.Track(session.Context(), session.ID(), stream, session.UserID(), m, false)
+			if success, _ := p.tracker.Track(session.Context(), session.ID(), stream, session.UserID(), m, false); success {
+				if p.config.GetSession().SingleMatch {
+					// Kick the user from any other matches they may be part of.
+					p.tracker.UntrackLocalByModes(session.ID(), matchStreamModes, stream)
+				}
+			}
 		}
 
 		label = &wrapperspb.StringValue{Value: l}
diff --git a/server/session_registry.go b/server/session_registry.go
index d6a1d7e67db7c6e41be4c9990f9c5ac8a4daf8fa..a1cb5bc8328fb687d24187e8d4b22e08bec333a9 100644
--- a/server/session_registry.go
+++ b/server/session_registry.go
@@ -16,7 +16,10 @@ package server
 
 import (
 	"context"
+	"github.com/heroiclabs/nakama-common/api"
+	"google.golang.org/protobuf/types/known/timestamppb"
 	"sync"
+	"time"
 
 	"github.com/gofrs/uuid"
 	"github.com/heroiclabs/nakama-common/rtapi"
@@ -53,7 +56,7 @@ type Session interface {
 	Send(envelope *rtapi.Envelope, reliable bool) error
 	SendBytes(payload []byte, reliable bool) error
 
-	Close(msg string, reason runtime.PresenceReason)
+	Close(msg string, reason runtime.PresenceReason, envelopes ...*rtapi.Envelope)
 }
 
 type SessionRegistry interface {
@@ -131,7 +134,22 @@ func (r *LocalSessionRegistry) SingleSession(ctx context.Context, tracker Tracke
 		session, ok := r.sessions.Load(foundSessionID)
 		if ok {
 			// No need to remove the session from the map, session.Close() will do that.
-			session.(Session).Close("server-side session disconnect", runtime.PresenceReasonDisconnect)
+			session.(Session).Close("server-side session disconnect", runtime.PresenceReasonDisconnect,
+				&rtapi.Envelope{Message: &rtapi.Envelope_Notifications{
+					Notifications: &rtapi.Notifications{
+						Notifications: []*api.Notification{
+							{
+								Id:         uuid.Must(uuid.NewV4()).String(),
+								Subject:    "single_socket",
+								Content:    "{}",
+								Code:       NotificationCodeSingleSocket,
+								SenderId:   "",
+								CreateTime: &timestamppb.Timestamp{Seconds: time.Now().Unix()},
+								Persistent: false,
+							},
+						},
+					},
+				}})
 		}
 	}
 }
diff --git a/server/session_ws.go b/server/session_ws.go
index f10b39d79f74a00a5ab1bbf831dbcab646445f7b..3719b1dbeb720e502e70af1eb9c6fc708a1bf78c 100644
--- a/server/session_ws.go
+++ b/server/session_ws.go
@@ -422,7 +422,7 @@ func (s *sessionWS) SendBytes(payload []byte, reliable bool) error {
 	}
 }
 
-func (s *sessionWS) Close(msg string, reason runtime.PresenceReason) {
+func (s *sessionWS) Close(msg string, reason runtime.PresenceReason, envelopes ...*rtapi.Envelope) {
 	s.Lock()
 	if s.stopped {
 		s.Unlock()
@@ -462,6 +462,48 @@ func (s *sessionWS) Close(msg string, reason runtime.PresenceReason) {
 	s.pingTimer.Stop()
 	close(s.outgoingCh)
 
+	// Send final messages, if any are specified.
+	for _, envelope := range envelopes {
+		var payload []byte
+		var err error
+		switch s.format {
+		case SessionFormatProtobuf:
+			payload, err = proto.Marshal(envelope)
+		case SessionFormatJson:
+			fallthrough
+		default:
+			if buf, err := s.protojsonMarshaler.Marshal(envelope); err == nil {
+				payload = buf
+			}
+		}
+		if err != nil {
+			s.logger.Warn("Could not marshal envelope", zap.Error(err))
+			continue
+		}
+
+		if s.logger.Core().Enabled(zap.DebugLevel) {
+			switch envelope.Message.(type) {
+			case *rtapi.Envelope_Error:
+				s.logger.Debug("Sending error message", zap.Binary("payload", payload))
+			default:
+				s.logger.Debug(fmt.Sprintf("Sending %T message", envelope.Message), zap.Any("envelope", envelope))
+			}
+		}
+
+		s.Lock()
+		if err := s.conn.SetWriteDeadline(time.Now().Add(s.writeWaitDuration)); err != nil {
+			s.Unlock()
+			s.logger.Warn("Failed to set write deadline", zap.Error(err))
+			continue
+		}
+		if err := s.conn.WriteMessage(s.wsMessageType, payload); err != nil {
+			s.Unlock()
+			s.logger.Warn("Could not write message", zap.Error(err))
+			continue
+		}
+		s.Unlock()
+	}
+
 	// Send close message.
 	if err := s.conn.WriteControl(websocket.CloseMessage, []byte{}, time.Now().Add(s.writeWaitDuration)); err != nil {
 		// This may not be possible if the socket was already fully closed by an error.