diff --git a/cmd/event.go b/cmd/event.go
index 3d380d9..21d8b4e 100644
--- a/cmd/event.go
+++ b/cmd/event.go
@@ -8,6 +8,7 @@ import (
 type runEvent struct {
 	threshold int
 	period    int
+	speakers  int
 	channel   string
 	verbose   bool
 }
@@ -23,6 +24,7 @@ func runEventCmd() *cobra.Command {
 	flags := cmd.Flags()
 	flags.IntVarP(&r.threshold, "threshold", "t", 10, "Threshold for rage judgement.")
 	flags.IntVarP(&r.period, "period", "p", 1200, "Observation period seconds for rage judgement. This CLI notify when there are more than threshold posts per period.")
+	flags.IntVarP(&r.speakers, "speakers", "s", 3, "This CLI notify when more speakers are participating.")
 	flags.StringVarP(&r.channel, "channel", "c", "random", "Notify channel.")
 	flags.BoolVarP(&r.verbose, "verbose", "v", false, "Enable verbose mode")
 
@@ -31,6 +33,6 @@ func runEventCmd() *cobra.Command {
 }
 
 func (r *runEvent) run(cmd *cobra.Command, args []string) {
-	s := event.NewServer(r.threshold, r.period, r.channel, r.verbose)
+	s := event.NewServer(r.threshold, r.period, r.speakers, r.channel, r.verbose)
 	s.Serve()
 }
diff --git a/cmd/rtm.go b/cmd/rtm.go
index 5fd02bc..790f2b3 100644
--- a/cmd/rtm.go
+++ b/cmd/rtm.go
@@ -8,6 +8,7 @@ import (
 type runRTM struct {
 	threshold int
 	period    int
+	speakers  int
 	channel   string
 	verbose   bool
 }
@@ -23,6 +24,7 @@ func runRTMCmd() *cobra.Command {
 	flags := cmd.Flags()
 	flags.IntVarP(&r.threshold, "threshold", "t", 10, "Threshold for rage judgement.")
 	flags.IntVarP(&r.period, "period", "p", 1200, "Observation period seconds for rage judgement. This CLI notify when there are more than threshold posts per period.")
+	flags.IntVarP(&r.speakers, "speakers", "s", 3, "This CLI notify when more speakers are participating.")
 	flags.StringVarP(&r.channel, "channel", "c", "random", "Notify channel.")
 	flags.BoolVarP(&r.verbose, "verbose", "v", false, "Enable verbose mode")
 
@@ -30,6 +32,6 @@ func runRTMCmd() *cobra.Command {
 }
 
 func (r *runRTM) run(cmd *cobra.Command, args []string) {
-	s := rtm.New(r.threshold, r.period, r.channel, r.verbose)
+	s := rtm.New(r.threshold, r.period, r.speakers, r.channel, r.verbose)
 	s.Start()
 }
diff --git a/event/server.go b/event/server.go
index c54ccc8..685e3e9 100644
--- a/event/server.go
+++ b/event/server.go
@@ -13,24 +13,20 @@ import (
 var notifyHistory = map[string]time.Time{}
 
 type Server struct {
-	threshold int
-	period    int
-	channel   string
-	token     string
-	logger    *logrus.Logger
-	detector  *rage.Rage
+	channel  string
+	token    string
+	logger   *logrus.Logger
+	detector *rage.Rage
 }
 
-func NewServer(threshold, period int, channel string, verbose bool) *Server {
+func NewServer(threshold, period, speakers int, channel string, verbose bool) *Server {
 	token := os.Getenv("SLACK_TOKEN")
 	logger := logrus.New()
 	if verbose {
 		logger.SetLevel(logrus.DebugLevel)
 	}
-	detector := rage.New(threshold, period, channel, logger, token)
+	detector := rage.New(threshold, period, speakers, channel, logger, token)
 	return &Server{
-		threshold,
-		period,
 		channel,
 		token,
 		logger,
diff --git a/rage/rage.go b/rage/rage.go
index 97c5947..09bcd77 100644
--- a/rage/rage.go
+++ b/rage/rage.go
@@ -20,18 +20,20 @@ func keys(m map[string]bool) []string {
 type Rage struct {
 	threshold     int
 	period        int
+	speakers      int
 	channel       string
 	logger        *logrus.Logger
 	slackClient   *slack.Client
 	notifyHistory map[string]time.Time
 }
 
-func New(threshold, period int, channel string, logger *logrus.Logger, token string) *Rage {
+func New(threshold, period, speakers int, channel string, logger *logrus.Logger, token string) *Rage {
 	notifyHistory := map[string]time.Time{}
 	slackClient := slack.New(token)
 	return &Rage{
 		threshold,
 		period,
+		speakers,
 		channel,
 		logger,
 		slackClient,
@@ -98,7 +100,7 @@ func (r *Rage) Detect(messageChannelID string, messageTimestamp string) error {
 	}
 
 	r.logger.Infof("%d speakers in the conversation", len(speakers))
-	if len(speakers) < 2 {
+	if len(speakers) < r.speakers {
 		return nil
 	}
 
diff --git a/rtm/rtm.go b/rtm/rtm.go
index 5d4eea0..793e418 100644
--- a/rtm/rtm.go
+++ b/rtm/rtm.go
@@ -9,15 +9,13 @@ import (
 )
 
 type RTM struct {
-	threshold int
-	period    int
-	channel   string
-	token     string
-	logger    *logrus.Logger
-	detector  *rage.Rage
+	channel  string
+	token    string
+	logger   *logrus.Logger
+	detector *rage.Rage
 }
 
-func New(threshold, period int, channel string, verbose bool) *RTM {
+func New(threshold, period, speakers int, channel string, verbose bool) *RTM {
 	token := os.Getenv("SLACK_TOKEN")
 	logger := logrus.New()
 	if verbose {
@@ -25,10 +23,8 @@ func New(threshold, period int, channel string, verbose bool) *RTM {
 	}
 	// We have to create classic slack app using RTM.
 	// Classic slack app require OAuth token to call REST API separately from bot token.
-	detector := rage.New(threshold, period, channel, logger, os.Getenv("OAUTH_TOKEN"))
+	detector := rage.New(threshold, period, speakers, channel, logger, os.Getenv("OAUTH_TOKEN"))
 	return &RTM{
-		threshold,
-		period,
 		channel,
 		token,
 		logger,