diff --git a/Makefile b/Makefile
index 74bb00e..e73e638 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ endif
 
 override APP_NAME=slack-duty-bot
 override MOD_NAME=github.com/insidieux/${APP_NAME}
-override GO_VERSION=1.12
+override GO_VERSION=1.13
 override CGO_ENABLED=0
 
 # build go binary variables
diff --git a/go.mod b/go.mod
index 796c528..0c93352 100644
--- a/go.mod
+++ b/go.mod
@@ -19,7 +19,7 @@ require (
 	github.com/kr/pty v1.1.8 // indirect
 	github.com/magiconair/properties v1.8.1 // indirect
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
-	github.com/nlopes/slack v0.6.0
+	github.com/nlopes/slack v0.6.1-0.20191106133607-d06c2a2b3249
 	github.com/pelletier/go-toml v1.4.0 // indirect
 	github.com/prometheus/client_golang v1.1.0 // indirect
 	github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4 // indirect
@@ -50,3 +50,5 @@ require (
 	google.golang.org/grpc v1.23.1 // indirect
 	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 )
+
+go 1.13
diff --git a/go.sum b/go.sum
index 0a89da0..6799778 100644
--- a/go.sum
+++ b/go.sum
@@ -129,6 +129,8 @@ github.com/nlopes/slack v0.2.0 h1:ygNVH3HWrOPFbzFoAmRKPcMcmYMmsLf+vPV9DhJdqJI=
 github.com/nlopes/slack v0.2.0/go.mod h1:jVI4BBK3lSktibKahxBF74txcK2vyvkza1z/+rRnVAM=
 github.com/nlopes/slack v0.6.0 h1:jt0jxVQGhssx1Ib7naAOZEZcGdtIhTzkP0nopK0AsRA=
 github.com/nlopes/slack v0.6.0/go.mod h1:JzQ9m3PMAqcpeCam7UaHSuBuupz7CmpjehYMayT6YOk=
+github.com/nlopes/slack v0.6.1-0.20191106133607-d06c2a2b3249 h1:Pr5gZa2VcmktVwq0lyC39MsN5tz356vC/pQHKvq+QBo=
+github.com/nlopes/slack v0.6.1-0.20191106133607-d06c2a2b3249/go.mod h1:JzQ9m3PMAqcpeCam7UaHSuBuupz7CmpjehYMayT6YOk=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/pelletier/go-toml v1.1.0 h1:cmiOvKzEunMsAxyhXSzpL5Q1CRKpVv0KQsnAIcSEVYM=
diff --git a/main.go b/main.go
index 91f6432..df0e2b5 100644
--- a/main.go
+++ b/main.go
@@ -233,7 +233,14 @@ func handleMessageEvent(rtm *slack.RTM, event *slack.MessageEvent) error {
 	//send message
 	var rtmOptions = make([]slack.RTMsgOption, 0)
 	if viper.GetBool("slack.threads") == true {
-		rtmOptions = append(rtmOptions, slack.RTMsgOptionTS(event.Timestamp))
+		var (
+			optionTS = event.Timestamp
+		)
+		// message already in timestamp
+		if event.ThreadTimestamp != `` {
+			optionTS = event.ThreadTimestamp
+		}
+		rtmOptions = append(rtmOptions, slack.RTMsgOptionTS(optionTS))
 	}
 	var outgoingMessage = rtm.NewOutgoingMessage(strings.Join(duties, ", "), event.Channel, rtmOptions...)
 	logrus.Debugf("Outgoing message: %+v", outgoingMessage)